static void check(int[] C, int choose) {
		int even = 0, odd = 0;
		for (int i = 0; i < C.length; ++i) {
			if ((i & 1) == 1) {
				odd += C[i];
			} else {
				even += C[i];
			}
		}
		if (choose == 0) {
			assert (even >= odd);
		} else {
			assert (odd >= even);
		}
	}