#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
#define REP(i,m,n) for(int i=(int)(m) ; i < (int) (n) ; ++i )
#define rep(i,n) REP(i,0,n)
#define square(x) pow(x,2.0)
#define sqrt(x) pow(x,0.5)
#define all(x) (x).begin(),(x).end()
#define F first
#define S second
#define max_queue(x) priority_queue<x>
#define min_queue(x) priority_queue<x, vector<x>, greater<x>>
#define big_sort(v) sort(all(v), [](int a, int b) { return a > b; })//大きい順にソート
using ll = long long;
using vi = vector<ll>;
using vvi = vector<vi>;
using vs = vector<string>;
using vd = vector<long double>;
#define co(x) cout << x << endl;
#define cins(n,v) rep(i,n){cin >> v.at(i);}
#define couts(v) rep(i,v.size()){cout << v.at(i) << endl;}
// aよりもbが大きいならばaをbで更新する
// (更新されたならばtrueを返す)
template <typename T>
bool chmax(T &a, const T& b) {
  if (a < b) {
    a = b;  // aをbで更新
    return true;
  }
  return false;
}
// aよりもbが小さいならばaをbで更新する
// (更新されたならばtrueを返す)
template <typename T>
bool chmin(T &a, const T& b) {
  if (a > b) {
    a = b;  // aをbで更新
    return true;
  }
  return false;
}
ll max(ll a,ll b){return (a>b ? a:b);}
ll min(ll a,ll b){return (a<b ? a:b);}
long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

const int MAX = 510000;
const int MOD = 1000000007;
long long fac[MAX], finv[MAX], inv[MAX];

// nCkのテーブルを作る前処理
void COMinit() {
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < MAX; i++){
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }
}
// 二項係数計算
long long COM(int n, int k){
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
// aのmodでの逆元 非再帰拡張 Euclid の互除法
long long modinv(long long a, long long mod) {
    long long b = mod, u = 1, v = 0;
    while (b) {
        long long t = a / b;
        a -= t * b; swap(a, b);
        u -= t * v; swap(u, v);
    }
    u %= mod;
    if (u < 0) u += mod;
    return u;
}
/*
#include <iostream> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#include <unordered_map> // unordered_map
#include <unordered_set> // unordered_set
#include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
*/
int main() {
  // srand((unsigned)time(NULL));
  // set<int> st;
  // queue<ll> q;
  // map<ll, ll> mp;
  ll t,ans=0,r,l;
  string str;
  cin >> t;
  rep(i, t){
    cin >> l>>r;
    l*=2;
    cout << (r<l ? 0:(r%2 ? (r-l+1)/2*(r-l+2):(r-l+2)/2*(r-l+1))) << endl;
  }
  // vector<int> v(n);
  // cins(n, v);
  // couts(v);
  // cout << (ans==0 ? "Yes" : "No") << endl;
  return 0;
}

#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n) ;i++)

using namespace std;
using p=pair<int,int>;
typedef long long ll;

int main() {
  int t;
  cin >> t;
  ll ans =0;
  rep(i,t){
    ll l,r;
    cin >> l >> r;
    ll sub = r-l;
    if(sub < l){
      cout << 0 << endl;
    }
    else{
      ll number = sub-l+1;
      if(number != 1){
        ans = (number + 1) * number / 2;
      }
      else if (number == 1){
        ans = 1;
      }
      cout << ans << endl;
      ans = 0;
    }
  }

  return 0;

}