#include <iostream>

using namespace std;
typedef long long ll;
int main(){
    int t; cin >> t;
    while(t){
        t--;
        ll i,n,m; cin >> n >> m;
        if(n<m) cout << (m - n + 4)*(m - n - 1)/2 + (m/2) - (m - n) << endl;
        else cout << m/2 << endl;
    }
}