#include <iostream>
using namespace std;
using i64 = long long;

const i64 mod = 998244353;

i64 modpow(i64 a, i64 b) {
    i64 res = 1;
    while (b) {
        if (b & 1) res = (res * a) % mod;
        a = (a * a) % mod;
        b >>= 1;
    }
    return res;
}

int main() {
    int t;
    cin >> t;
    while (t--) {
        i64 n, k;
        cin >> n >> k;
        i64 ans = 0;
        for (int i = 1; i <= k; i++) {
            ans = (ans + modpow(i + 1, n)) % mod;
        }
        cout << ans << "\n";
    }
}