#include <iostream>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)

using m32 = atcoder::modint998244353;

int main(){
    m32 ans = 0;
    int N, K; cin >> N >> K;
    for(int max2=1; max2<=K; max2++){
        m32 tmp = 0;
        tmp += m32(max2-1) * m32(K-max2+1).pow(N-1) * N;
        tmp -= m32(max2-1) * m32(K-max2).pow(N-1) * N;
        ans += tmp * max2;
    }
    for(int max2=1; max2<=K; max2++){
        m32 tmp = 0;
        tmp += m32(K-max2+1).pow(N);
        tmp -= m32(K-max2).pow(N-1) * N;
        tmp -= m32(K-max2).pow(N);
        ans += tmp * max2;
    }
    ans = m32(K).pow(N) * (K+1) - ans;
    cout << ans.val() << '\n';
    return 0;
}

struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;