#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY[]{1, 0, -1, 0}, DX[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}, DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

void solve() {
  ll n, m; cin >> n >> m;
  const ll x = m - n;
  cout << (m <= n ? m / 2 : x * (x + 1) / 2 + (x - 1) + n - (m + 1) / 2) << '\n';
}

int main() {
  int t; cin >> t;
  while (t--) solve();
  return 0;

  // vector<int> p(n);
  // iota(ALL(p), 0);
  // int ans = INF;
  // do {
  //   int cost = 0;
  //   vector<int> exists(n, true);
  //   REP(i, n - 1) {
  //     int mn = INF;
  //     REP(j, n) {
  //       if (j != p[i] && exists[j]) chmin(mn, (p[i] + 1 + j + 1) % m);
  //     }
  //     cost += mn;
  //     exists[p[i]] = false;
  //   }
  //   chmin(ans, cost);
  // } while (next_permutation(ALL(p)));
}