#include <stdio.h>

long long solve(long long L, long long R)
{
	long long X = ((L + R) - L * 2 + 1) % 8;
	if (X == 0 || X == 6 || X == 7) return 0;
	else if (X == 2 || X == 3 || X == 4) return 1;
	else if (X == 1) return L + R;
	else return (L + R) ^ 1;
}

int main()
{
	int t, T;
	long long L, R;
	scanf("%d", &T);
	for (t = 1; t <= T; t++) {
		scanf("%lld %lld", &L, &R);
		printf("%lld\n", solve(L, R));
	}
	fflush(stdout);
	return 0;
}