#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int t;
  cin >> t;
  while (t--) {
    int n, k;
    cin >> n >> k;
    mint ans = 0;
    for (int i = 1; i <= k; ++i) ans += mint(i + 1).pow(n);
    cout << ans.val() << '\n';
  }
  return 0;
}