http://math.stackexchange.com/q/1512083/86776

model.txt

/* Objective function */
max: +A1T +A2T +A3T +A4T +A5T +A6T +A7T +A8T +A9T +A10T +A11T +A12T +A13T +A14T +A15T +A16T +A17T +A18T +A19T
 +A20T +A21T +A22T +A23T +A24T +A25T +A26T +A27T +A28T +A29T +A30T;

/* Constraints */
A1: +U0B = 10;
A2: +U0D = 0;
A3: +U0F = 0;
A4: +U0C = 0;
A5: +U0E = 0;
B1: +A1Q +A1R +A1S +A1T <= 1;
B2: +A2Q +A2R +A2S +A2T <= 1;
B3: +A3Q +A3R +A3S +A3T <= 1;
B4: +A4Q +A4R +A4S +A4T <= 1;
B5: +A5Q +A5R +A5S +A5T <= 1;
B6: +A6Q +A6R +A6S +A6T <= 1;
B7: +A7Q +A7R +A7S +A7T <= 1;
B8: +A8Q +A8R +A8S +A8T <= 1;
B9: +A9Q +A9R +A9S +A9T <= 1;
B10: +A10Q +A10R +A10S +A10T <= 1;
B11: +A11Q +A11R +A11S +A11T <= 1;
B12: +A12Q +A12R +A12S +A12T <= 1;
B13: +A13Q +A13R +A13S +A13T <= 1;
B14: +A14Q +A14R +A14S +A14T <= 1;
B15: +A15Q +A15R +A15S +A15T <= 1;
B16: +A16Q +A16R +A16S +A16T <= 1;
B17: +A17Q +A17R +A17S +A17T <= 1;
B18: +A18Q +A18R +A18S +A18T <= 1;
B19: +A19Q +A19R +A19S +A19T <= 1;
B20: +A20Q +A20R +A20S +A20T <= 1;
B21: +A21Q +A21R +A21S +A21T <= 1;
B22: +A22Q +A22R +A22S +A22T <= 1;
B23: +A23Q +A23R +A23S +A23T <= 1;
B24: +A24Q +A24R +A24S +A24T <= 1;
B25: +A25Q +A25R +A25S +A25T <= 1;
B26: +A26Q +A26R +A26S +A26T <= 1;
B27: +A27Q +A27R +A27S +A27T <= 1;
B28: +A28Q +A28R +A28S +A28T <= 1;
B29: +A29Q +A29R +A29S +A29T <= 1;
B30: +A30Q +A30R +A30S +A30T <= 1;
C1B: +U0B -2 A1Q -U1B = 0;
C1D: +U0D +A1T -U1D = 0;
C1F: +U0F +A1Q +A1R +A1S -A1T -U1F = 0;
C1C: +U0C -4 A1R +A1T -U1C = 0;
C1E: +U0E -2 A1S +A1T -U1E = 0;
C2B: +U1B -2 A2Q -U2B = 0;
C2D: +U1D +A2T -U2D = 0;
C2F: +U1F +A2Q +A2R +A2S -A2T -U2F = 0;
C2C: +U1C -4 A2R +A2T -U2C = 0;
C2E: +U1E -2 A2S +A2T -U2E = 0;
C3B: +U2B -2 A3Q -U3B = 0;
C3D: +U2D +A3T -U3D = 0;
C3F: +U2F +A3Q +A3R +A3S -A3T -U3F = 0;
C3C: +U2C -4 A3R +A3T -U3C = 0;
C3E: +U2E -2 A3S +A3T -U3E = 0;
C4B: +U3B -2 A4Q -U4B = 0;
C4D: +U3D +A4T -U4D = 0;
C4F: +U3F +A4Q +A4R +A4S -A4T -U4F = 0;
C4C: +U3C -4 A4R +A4T -U4C = 0;
C4E: +U3E -2 A4S +A4T -U4E = 0;
C5B: +U4B -2 A5Q -U5B = 0;
C5D: +U4D +A5T -U5D = 0;
C5F: +U4F +A5Q +A5R +A5S -A5T -U5F = 0;
C5C: +U4C -4 A5R +A5T -U5C = 0;
C5E: +U4E -2 A5S +A5T -U5E = 0;
C6B: +U5B -2 A6Q -U6B = 0;
C6D: +U5D +A6T -U6D = 0;
C6F: +U5F +A6Q +A6R +A6S -A6T -U6F = 0;
C6C: +U5C -4 A6R +A6T -U6C = 0;
C6E: +U5E -2 A6S +A6T -U6E = 0;
C7B: +U6B -2 A7Q -U7B = 0;
C7D: +U6D +A7T -U7D = 0;
C7F: +U6F +A7Q +A7R +A7S -A7T -U7F = 0;
C7C: +U6C -4 A7R +A7T -U7C = 0;
C7E: +U6E -2 A7S +A7T -U7E = 0;
C8B: +U7B -2 A8Q -U8B = 0;
C8D: +U7D +A8T -U8D = 0;
C8F: +U7F +A8Q +A8R +A8S -A8T -U8F = 0;
C8C: +U7C -4 A8R +A8T -U8C = 0;
C8E: +U7E -2 A8S +A8T -U8E = 0;
C9B: +U8B -2 A9Q -U9B = 0;
C9D: +U8D +A9T -U9D = 0;
C9F: +U8F +A9Q +A9R +A9S -A9T -U9F = 0;
C9C: +U8C -4 A9R +A9T -U9C = 0;
C9E: +U8E -2 A9S +A9T -U9E = 0;
C10B: +U9B -2 A10Q -U10B = 0;
C10D: +U9D +A10T -U10D = 0;
C10F: +U9F +A10Q +A10R +A10S -A10T -U10F = 0;
C10C: +U9C -4 A10R +A10T -U10C = 0;
C10E: +U9E -2 A10S +A10T -U10E = 0;
C11B: +U10B -2 A11Q -U11B = 0;
C11D: +U10D +A11T -U11D = 0;
C11F: +U10F +A11Q +A11R +A11S -A11T -U11F = 0;
C11C: +U10C -4 A11R +A11T -U11C = 0;
C11E: +U10E -2 A11S +A11T -U11E = 0;
C12B: +U11B -2 A12Q -U12B = 0;
C12D: +U11D +A12T -U12D = 0;
C12F: +U11F +A12Q +A12R +A12S -A12T -U12F = 0;
C12C: +U11C -4 A12R +A12T -U12C = 0;
C12E: +U11E -2 A12S +A12T -U12E = 0;
C13B: +U12B -2 A13Q -U13B = 0;
C13D: +U12D +A13T -U13D = 0;
C13F: +U12F +A13Q +A13R +A13S -A13T -U13F = 0;
C13C: +U12C -4 A13R +A13T -U13C = 0;
C13E: +U12E -2 A13S +A13T -U13E = 0;
C14B: +U13B -2 A14Q -U14B = 0;
C14D: +U13D +A14T -U14D = 0;
C14F: +U13F +A14Q +A14R +A14S -A14T -U14F = 0;
C14C: +U13C -4 A14R +A14T -U14C = 0;
C14E: +U13E -2 A14S +A14T -U14E = 0;
C15B: +U14B -2 A15Q -U15B = 0;
C15D: +U14D +A15T -U15D = 0;
C15F: +U14F +A15Q +A15R +A15S -A15T -U15F = 0;
C15C: +U14C -4 A15R +A15T -U15C = 0;
C15E: +U14E -2 A15S +A15T -U15E = 0;
C16B: +U15B -2 A16Q -U16B = 0;
C16D: +U15D +A16T -U16D = 0;
C16F: +U15F +A16Q +A16R +A16S -A16T -U16F = 0;
C16C: +U15C -4 A16R +A16T -U16C = 0;
C16E: +U15E -2 A16S +A16T -U16E = 0;
C17B: +U16B -2 A17Q -U17B = 0;
C17D: +U16D +A17T -U17D = 0;
C17F: +U16F +A17Q +A17R +A17S -A17T -U17F = 0;
C17C: +U16C -4 A17R +A17T -U17C = 0;
C17E: +U16E -2 A17S +A17T -U17E = 0;
C18B: +U17B -2 A18Q -U18B = 0;
C18D: +U17D +A18T -U18D = 0;
C18F: +U17F +A18Q +A18R +A18S -A18T -U18F = 0;
C18C: +U17C -4 A18R +A18T -U18C = 0;
C18E: +U17E -2 A18S +A18T -U18E = 0;
C19B: +U18B -2 A19Q -U19B = 0;
C19D: +U18D +A19T -U19D = 0;
C19F: +U18F +A19Q +A19R +A19S -A19T -U19F = 0;
C19C: +U18C -4 A19R +A19T -U19C = 0;
C19E: +U18E -2 A19S +A19T -U19E = 0;
C20B: +U19B -2 A20Q -U20B = 0;
C20D: +U19D +A20T -U20D = 0;
C20F: +U19F +A20Q +A20R +A20S -A20T -U20F = 0;
C20C: +U19C -4 A20R +A20T -U20C = 0;
C20E: +U19E -2 A20S +A20T -U20E = 0;
C21B: +U20B -2 A21Q -U21B = 0;
C21D: +U20D +A21T -U21D = 0;
C21F: +U20F +A21Q +A21R +A21S -A21T -U21F = 0;
C21C: +U20C -4 A21R +A21T -U21C = 0;
C21E: +U20E -2 A21S +A21T -U21E = 0;
C22B: +U21B -2 A22Q -U22B = 0;
C22D: +U21D +A22T -U22D = 0;
C22F: +U21F +A22Q +A22R +A22S -A22T -U22F = 0;
C22C: +U21C -4 A22R +A22T -U22C = 0;
C22E: +U21E -2 A22S +A22T -U22E = 0;
C23B: +U22B -2 A23Q -U23B = 0;
C23D: +U22D +A23T -U23D = 0;
C23F: +U22F +A23Q +A23R +A23S -A23T -U23F = 0;
C23C: +U22C -4 A23R +A23T -U23C = 0;
C23E: +U22E -2 A23S +A23T -U23E = 0;
C24B: +U23B -2 A24Q -U24B = 0;
C24D: +U23D +A24T -U24D = 0;
C24F: +U23F +A24Q +A24R +A24S -A24T -U24F = 0;
C24C: +U23C -4 A24R +A24T -U24C = 0;
C24E: +U23E -2 A24S +A24T -U24E = 0;
C25B: +U24B -2 A25Q -U25B = 0;
C25D: +U24D +A25T -U25D = 0;
C25F: +U24F +A25Q +A25R +A25S -A25T -U25F = 0;
C25C: +U24C -4 A25R +A25T -U25C = 0;
C25E: +U24E -2 A25S +A25T -U25E = 0;
C26B: +U25B -2 A26Q -U26B = 0;
C26D: +U25D +A26T -U26D = 0;
C26F: +U25F +A26Q +A26R +A26S -A26T -U26F = 0;
C26C: +U25C -4 A26R +A26T -U26C = 0;
C26E: +U25E -2 A26S +A26T -U26E = 0;
C27B: +U26B -2 A27Q -U27B = 0;
C27D: +U26D +A27T -U27D = 0;
C27F: +U26F +A27Q +A27R +A27S -A27T -U27F = 0;
C27C: +U26C -4 A27R +A27T -U27C = 0;
C27E: +U26E -2 A27S +A27T -U27E = 0;
C28B: +U27B -2 A28Q -U28B = 0;
C28D: +U27D +A28T -U28D = 0;
C28F: +U27F +A28Q +A28R +A28S -A28T -U28F = 0;
C28C: +U27C -4 A28R +A28T -U28C = 0;
C28E: +U27E -2 A28S +A28T -U28E = 0;
C29B: +U28B -2 A29Q -U29B = 0;
C29D: +U28D +A29T -U29D = 0;
C29F: +U28F +A29Q +A29R +A29S -A29T -U29F = 0;
C29C: +U28C -4 A29R +A29T -U29C = 0;
C29E: +U28E -2 A29S +A29T -U29E = 0;
C30B: +U29B -2 A30Q -U30B = 0;
C30D: +U29D +A30T -U30D = 0;
C30F: +U29F +A30Q +A30R +A30S -A30T -U30F = 0;
C30C: +U29C -4 A30R +A30T -U30C = 0;
C30E: +U29E -2 A30S +A30T -U30E = 0;

/* Variable bounds */
A1Q <= 1;
A1R <= 1;
A1S <= 1;
A1T <= 1;
A2Q <= 1;
A2R <= 1;
A2S <= 1;
A2T <= 1;
A3Q <= 1;
A3R <= 1;
A3S <= 1;
A3T <= 1;
A4Q <= 1;
A4R <= 1;
A4S <= 1;
A4T <= 1;
A5Q <= 1;
A5R <= 1;
A5S <= 1;
A5T <= 1;
A6Q <= 1;
A6R <= 1;
A6S <= 1;
A6T <= 1;
A7Q <= 1;
A7R <= 1;
A7S <= 1;
A7T <= 1;
A8Q <= 1;
A8R <= 1;
A8S <= 1;
A8T <= 1;
A9Q <= 1;
A9R <= 1;
A9S <= 1;
A9T <= 1;
A10Q <= 1;
A10R <= 1;
A10S <= 1;
A10T <= 1;
A11Q <= 1;
A11R <= 1;
A11S <= 1;
A11T <= 1;
A12Q <= 1;
A12R <= 1;
A12S <= 1;
A12T <= 1;
A13Q <= 1;
A13R <= 1;
A13S <= 1;
A13T <= 1;
A14Q <= 1;
A14R <= 1;
A14S <= 1;
A14T <= 1;
A15Q <= 1;
A15R <= 1;
A15S <= 1;
A15T <= 1;
A16Q <= 1;
A16R <= 1;
A16S <= 1;
A16T <= 1;
A17Q <= 1;
A17R <= 1;
A17S <= 1;
A17T <= 1;
A18Q <= 1;
A18R <= 1;
A18S <= 1;
A18T <= 1;
A19Q <= 1;
A19R <= 1;
A19S <= 1;
A19T <= 1;
A20Q <= 1;
A20R <= 1;
A20S <= 1;
A20T <= 1;
A21Q <= 1;
A21R <= 1;
A21S <= 1;
A21T <= 1;
A22Q <= 1;
A22R <= 1;
A22S <= 1;
A22T <= 1;
A23Q <= 1;
A23R <= 1;
A23S <= 1;
A23T <= 1;
A24Q <= 1;
A24R <= 1;
A24S <= 1;
A24T <= 1;
A25Q <= 1;
A25R <= 1;
A25S <= 1;
A25T <= 1;
A26Q <= 1;
A26R <= 1;
A26S <= 1;
A26T <= 1;
A27Q <= 1;
A27R <= 1;
A27S <= 1;
A27T <= 1;
A28Q <= 1;
A28R <= 1;
A28S <= 1;
A28T <= 1;
A29Q <= 1;
A29R <= 1;
A29S <= 1;
A29T <= 1;
A30Q <= 1;
A30R <= 1;
A30S <= 1;
A30T <= 1;

/* Integer definitions */
int U0B,U0D,U0F,U0C,U0E,A1Q,A1R,A1S,A1T,U1B,U1D,U1F,U1C,U1E,A2Q,A2R,A2S,A2T,U2B,U2D,U2F,U2C,U2E,A3Q,A3R,A3S,A3T,U3B,U3D,U3F,U3C,U3E,A4Q,A4R,A4S,A4T,U4B,U4D,U4F,U4C,U4E,A5Q,A5R,A5S,A5T,U5B,U5D,U5F,U5C,U5E,A6Q,A6R,A6S,A6T,U6B,U6D,U6F,U6C,U6E,A7Q,A7R,A7S,A7T,U7B,U7D,U7F,U7C,U7E,A8Q,A8R,A8S,A8T,U8B,U8D,U8F,U8C,U8E,A9Q,A9R,A9S,A9T,U9B,U9D,U9F,U9C,U9E,A10Q,A10R,A10S,A10T,U10B,U10D,U10F,U10C,U10E,A11Q,A11R,A11S,A11T,U11B,U11D,U11F,U11C,U11E,A12Q,A12R,A12S,A12T,U12B,U12D,U12F,U12C,U12E,A13Q,A13R,A13S,A13T,U13B,U13D,U13F,U13C,U13E,A14Q,A14R,A14S,A14T,U14B,U14D,U14F,U14C,U14E,A15Q,A15R,A15S,A15T,U15B,U15D,U15F,U15C,U15E,A16Q,A16R,A16S,A16T,U16B,U16D,U16F,U16C,U16E,A17Q,A17R,A17S,A17T,U17B,U17D,U17F,U17C,U17E,A18Q,A18R,A18S,A18T,U18B,U18D,U18F,U18C,U18E,A19Q,A19R,A19S,A19T,U19B,U19D,U19F,U19C,U19E,A20Q,A20R,A20S,A20T,U20B,U20D,U20F,U20C,U20E,A21Q,A21R,A21S,A21T,U21B,U21D,U21F,U21C,U21E,A22Q,A22R,A22S,A22T,U22B,U22D,U22F,U22C,U22E,A23Q,A23R,A23S,A23T,U23B,U23D,U23F,U23C,U23E,A24Q,A24R,A24S,A24T,U24B,U24D,U24F,U24C,U24E,A25Q,A25R,A25S,A25T,U25B,U25D,U25F,U25C,U25E,A26Q,A26R,A26S,A26T,U26B,U26D,U26F,U26C,U26E,A27Q,A27R,A27S,A27T,U27B,U27D,U27F,U27C,U27E,A28Q,A28R,A28S,A28T,U28B,U28D,U28F,U28C,U28E,A29Q,A29R,A29S,A29T,U29B,U29D,U29F,U29C,U29E,A30Q,A30R,A30S,A30T,U30B,U30D,U30F,U30C,U30E;