#include <bits/stdc++.h>

#define rep(i, n) for(int i=0; i<(int)(n); i++)
#define FILL0(x) memset(x,0,sizeof(x))
#define FILL1(x) memset(x,-1,sizeof(x))

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
 

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);

    int t;
    cin >> t;


    ll l, r;
    rep(i, t){
    
        cin >> l >> r;
        
        ll ans = max(0LL,(r-l-l+1))*max(0LL,(r-l-l+1+1))/2;

        cout << ans << endl;
    }




    return 0;

}

#include <iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<map>
#include<set>
#include<stack>
#include<queue>
#include<math.h>
using namespace std;
typedef long long ll;
#define int long long
#define double long double
typedef vector<int> VI;
typedef pair<int, int> pii;
typedef vector<pii> VP;
typedef vector<string> VS;
typedef priority_queue<int> PQ;
template<class T>bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; }
#define fore(i,a) for(auto &i:a)
#define REP(i,n) for(int i=0;i<n;i++)
#define eREP(i,n) for(int i=0;i<=n;i++)
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define eFOR(i,a,b) for(int i=(a);i<=(b);++i)
#define SORT(c) sort((c).begin(),(c).end())
#define rSORT(c) sort((c).rbegin(),(c).rend())
#define LB(x,a) lower_bound((x).begin(),(x).end(),(a))
#define UB(x,a) upper_bound((x).begin(),(x).end(),(a))
#define INF 1000000000
#define LLINF 9223372036854775807
#define mod 1000000007
#define eps 1e-12 
//priority_queue<int,vector<int>, greater<int> > q2;

int solve(int L, int R) {
	int res = 0;
	int tmp = R - L;
	
	if (tmp < L)return 0;
	int ans = tmp - L + 1;

	//cout << ans << endl;
	res = ans * (ans + 1) / 2;
	return res;
}

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int t; cin >> t;
	while (t--) {
		int A, B, C; cin >> A >> B;
		cout << solve(A, B) << endl;
	}

	return 0;
}

