def main():     
    import sys
    input = sys.stdin.buffer.readline
    for _ in range(int(input())):
        n, m = map(int, input().split())
        if m <= n: print(m // 2)
        else:
            x = m - n
            print(x * (x + 1) // 2 - 1 + (x - 1) + m // 2 - x)
if __name__ == '__main__':
    main()