import sys
#input = sys.stdin.readline #文字列につけてはダメ
#input = sys.stdin.buffer.readline #文字列につけてはダメ
#sys.setrecursionlimit(1000000)
#import bisect
#import itertools
#import random
#from heapq import heapify, heappop, heappush
#from collections import defaultdict 
#from collections import deque
#import copy
#from functools import lru_cache


def main():
    t = int(input())
    for _ in range(t):
        n,m = map(int,input().split())
        if n >= m:
            ans = m//2
            print(ans);continue
        ans = -2
        ans += m//2
        x = m-n
        ans += (1+x)*x//2
        print(ans)
        

if __name__ == '__main__':
    main()