__kernel void matrix_add(__global double *res, __global const double *A, __global double *B) {
int n = get_global_id(0);
for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			res[i*n + j] = A[i*n + j] + B[i*n + j];
		}
	}
}