__kernel void sumReduction(__global int *A, __global int* C, int offset)
    {
        int global_id = get_global_id(0);
        //if(get_global_size(0) <  5)
          //  printf("Thread id = %d", global_id);
        int start = global_id * offset;
        int end = start + offset;
        int i;
        for(i=start; i<end; i++)
        {
            C[global_id] += A[i];
        }
    }