#include <bits/stdc++.h>
using namespace std;

constexpr int mod = 998244353;

long long fac[200005], finv[200005], inv[200005];

void COMinit() {
    fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1;
    for (int i = 2; i < 200005; 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;
    }
}

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;
}

long long modpow(long long a,long long b) {
    long long ans = 1;
    while(b) {
        if(b & 1) {
            (ans *= a) %= mod;
        }
        (a *= a) %= mod;
        b /= 2;
    }
    return ans;
}

long long dp[2022][2022],fac1[2022][2022];

int main() {
    int N,M;
    cin >> N >> M;
    dp[0][0] = 1;
    for(int i = 0; i < N; i++) {
        for(int j = 0; j < N; j++) {
            dp[i+1][j] += dp[i][j]*j%mod;
            dp[i+1][j] %= mod;
            dp[i+1][j+1] += dp[i][j];
            dp[i+1][j+1] %= mod;
        }
    }
    COMinit();
    for(int i = 1; i < N; i++) {
        for(int j = 0; j < N; j++) {
            dp[N][j] += dp[i][j]*modpow(M+1,N-i)%mod*COM(N,i)%mod;
            dp[N][j] %= mod;
        }
    }
    long long sum = 0;
    for(int i = 1; i <= N; i++) {
        fac1[i][i] = M+2-i;
        for(int j = i+1; j <= N; j++) {
            fac1[i][j] = fac1[i][j-1]*(M+2-j)%mod;
        }
    }
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= min(M+1,N); j++) {
            if(i <= j) {
                sum += dp[N][j]*COM(j,i)%mod*fac[i]%mod*((i == j)?1:fac1[i+1][j])%mod;
                sum %= mod;
            }
        }
    }
    cout << sum << endl;
}