gistfile1.txt

- (void)cpsSquence:(NSArray *)is
{
    [self cpsSquence:is atIndex:0];
}

- (void)cpsSequence:(NSArray *)is atIndex:(NSUInteger)idx
{
    if ([is count] > idx)
    {
        [[is objectAtIndex:idx] runWithCompletionBlock:^ ()
         {
             [self cpsSequence:is atIndex:idx+1];
         }];
    }
}