Solidity 言語仕様　基本編 ref: https://qiita.com/blueplanet/items/ecd3f4d5552e07e9ef2c

file0.txt

contract SingleNumRegister {
    uint storedData;

    function set(uint x) {
        storedData = x;
    }

    function get() constant returns (uint retVal) {
        return storedData;
    }
}