#include <stdio.h>

long long solve(int N, int M)
{
	if (M <= N) return M / 2;
	else return (N * 2 - M) / 2 + (M - N - 2) + (long long)(M - N + 1) * (M - N) / 2;
}

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