//#include <bits/stdc++.h>
//using namespace std;
//using ll=long long;
//#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
//#include "po167_library/fps/FPS_pow.hpp"
//using mint = atcoder::modint998244353;
//
//int main() {
//    int N;
//    ll K;
//    cin >> N >> K;
//    vector<mint> fact(N + 1, 1), invfact(N + 1);
//    rep(i, 0, N) fact[i + 1] = fact[i] * (i + 1);
//    invfact[N] = fact[N].inv();
//    for (int i = N; i > 0; i--){
//        invfact[i - 1] = invfact[i] * i;
//    }
//    vector<mint> f(N + 1);
//    rep(i, 0, N + 1){
//        f[i] = invfact[i];
//        f[i] *= ((mint)(N - i)).pow(i);
//    }
//    f = po167::FPS_pow(f, K - 1);
//
//    mint ans = 0;
//    rep(i, 1, N + 1){
//        mint tmp = f[N - i];
//        tmp *= invfact[i];
//        tmp *= ((mint)(N - i)).pow(i - 1);
//        tmp *= i;
//        tmp *= i;
//        ans += tmp;
//    }
//    ans *= fact[N];
//    ans *= K;
//    cout << ans.val() << "\n";
//}
///*
// * C[i] = a であるような i が K 個あるとする。
// * 被りなし (N - K)^{K}
// * 1 つ被り (N - K)^{K - 1} K^{2}
// * 思ったより簡単だった。。、
// */
#line 1 "g.cpp"
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#line 2 "/Users/Shared/po167_library/fps/FPS_pow.hpp"

#line 4 "/Users/Shared/po167_library/fps/FPS_pow.hpp"
#include <atcoder/convolution>

#line 4 "/Users/Shared/po167_library/fps/FPS_cyclic_convolution.hpp"

namespace po167{
// |f| = |g| = 2 ^ n
template<class T>
std::vector<T> FPS_cyclic_convolution(std::vector<T> f, std::vector<T> g){
    atcoder::internal::butterfly(f);
    atcoder::internal::butterfly(g);
    for (int i = 0; i < (int)f.size(); i++) f[i] *= g[i];
    atcoder::internal::butterfly_inv(f);
    T iz = (T)(1) / (T)(f.size());
    for (int i = 0; i < (int)f.size(); i++) f[i] *= iz;
    return f;
}
}
#line 3 "/Users/Shared/po167_library/fps/FPS_differetial.hpp"

namespace po167{
// return f'
template <class T>
std::vector<T> FPS_differential(std::vector<T> f){
    if (f.empty()) return f;
    for (int i = 0; i < (int)f.size() - 1; i++){
        f[i] = f[i + 1] * (T)(i + 1);
    }
    f.pop_back();
    return f;
}
}
#line 3 "/Users/Shared/po167_library/fps/FPS_integral.hpp"

namespace po167{
template <class T>
std::vector<T> FPS_integral(std::vector<T> f){
    if (f.empty()) return f;
    std::vector<T> num_inv((int)f.size() + 1);
    num_inv[0] = 1;
    num_inv[1] = 1;
    auto m = T::mod();
    for (int i = 2; i <= (int)f.size(); i++){
        num_inv[i] = (0 - num_inv[m % i]) * (T)(m / i);
    }
    f.reserve((int)f.size() + 1);
    f.push_back(0);
    for (int i = (int)f.size() - 1; i > 0; i--){
        f[i] = f[i - 1] * num_inv[i];
    }
    f[0] = 0;
    return f;
}
}
#line 4 "/Users/Shared/po167_library/fps/FPS_inv.hpp"

namespace po167{
// return 1 / f
template <class T>
std::vector<T> FPS_inv(std::vector<T> f, int len = -1){
    if (len == -1) len = f.size();
    assert(f[0] != 0);
    std::vector<T> g = {1 / f[0]};
    int s = 1;
    while(s < len){
        // g = 2g_s - f(g_s)^2 (mod x ^ (2 * s))
        // g = g - (fg - 1)g
        // (fg - 1) = 0 (mod x ^ (s))
        std::vector<T> n_g(s * 2, 0);
        std::vector<T> f_s(s * 2, 0);
        g.resize(s * 2);
        for (int i = 0; i < s * 2; i++){
            if (int(f.size()) > i) f_s[i] = f[i];
            n_g[i] = g[i];
        }
        atcoder::internal::butterfly(g);
        atcoder::internal::butterfly(f_s);
        for (int i = 0; i < s * 2; i++){
            f_s[i] *= g[i];
        }
        atcoder::internal::butterfly_inv(f_s);
        T iz = 1 / (T)(s * 2);
        for (int i = s; i < s * 2; i++){
            f_s[i] *= iz;
        }
        for (int i = 0; i < s; i++){
            f_s[i] = 0;
        }
        atcoder::internal::butterfly(f_s);
        for (int i = 0; i < s * 2; i++){
            f_s[i] *= g[i];
        }
        atcoder::internal::butterfly_inv(f_s);
        for (int i = s; i < s * 2; i++){
            n_g[i] -= f_s[i] * iz;
        }
        std::swap(n_g, g);
        s *= 2;
    }
    g.resize(len);
    return g;
}
}
#line 8 "/Users/Shared/po167_library/fps/FPS_exp.hpp"

namespace po167{
template<class T>
std::vector<T> FPS_exp(std::vector<T> f, int len = -1){
    if (len == -1) len = f.size();
    if (len == 0) return {};
    if (len == 1) return {T(1)};
    assert(!f.empty() && f[0] == 0);
    int s = 1;
    // simple
    std::vector<T> g = {T(1)};
    while (s < len){
        // g' / g
        // A * B
        std::vector<T> A = g, B = g;
        A = FPS_differential(A);
        B = FPS_inv(B, 2 * s);
        A.resize(2 * s);
        A = FPS_cyclic_convolution(A, B);
        A.pop_back();
        A = FPS_integral(A);
        for (int i = 0; i < s; i++) A[i] = 0;
        for (int i = s; i < s * 2; i++) A[i] = (i < (int)f.size() ? f[i] : 0) - A[i];
        // g_hat = g (1 - g + f)
        // g += B = g * A
        g.resize(2 * s);
        B = FPS_cyclic_convolution(A, g);
        for (int i = s; i < s * 2; i++) g[i] = B[i];
        s *= 2;
    }
    g.resize(len);
    return g;
}
}
#line 6 "/Users/Shared/po167_library/fps/FPS_log.hpp"

namespace po167{
template<class T>
std::vector<T> FPS_log(std::vector<T> f, int len = -1){
    if (len == -1) len = f.size();
    if (len == 0) return {};
    if (len == 1) return {T(0)};
    assert(!f.empty() && f[0] == 1);
    std::vector<T> res = atcoder::convolution(FPS_differential(f), FPS_inv(f, len));
    res.resize(len - 1);
    return FPS_integral(res);
}
}
#line 8 "/Users/Shared/po167_library/fps/FPS_pow.hpp"

namespace po167{
template<class T>
std::vector<T> FPS_pow(std::vector<T> f,long long M, int len = -1){
    if (len == -1) len = f.size();
    std::vector<T> res(len, 0);
    if (M == 0){
        res[0] = 1;
        return res;
    }
    for (int i = 0; i < (int)f.size(); i++){
        if (f[i] == 0) continue;
        if (i > (len - 1) / M) break;
        std::vector<T> g((int)f.size() - i);
        T v = (T)(1) / (T)(f[i]);
        for (int j = i; j < (int)f.size(); j++){
            g[j - i] = f[j] * v;
        }
        long long zero = i * M;
        if (i) len -= i * M;
        g = FPS_log(g, len);
        for (T &x : g) x *= M;
        g = FPS_exp(g, len);
        v = (T)(1) / v;
        T c = 1;
        while (M){
            if (M & 1) c = c * v;
            v = v * v;
            M >>= 1;
        }
        for (int i = 0; i < len; i++) res[i + zero] = g[i] * c;
        return res;
    }
    return res;
}
}
#line 6 "g.cpp"
using mint = atcoder::modint998244353;

int main() {
    int N;
    ll K;
    cin >> N >> K;
    vector<mint> fact(N + 1, 1), invfact(N + 1);
    rep(i, 0, N) fact[i + 1] = fact[i] * (i + 1);
    invfact[N] = fact[N].inv();
    for (int i = N; i > 0; i--){
        invfact[i - 1] = invfact[i] * i;
    }
    vector<mint> f(N + 1);
    rep(i, 0, N + 1){
        f[i] = invfact[i];
        f[i] *= ((mint)(N - i)).pow(i);
    }
    f = po167::FPS_pow(f, K - 1);

    mint ans = 0;
    rep(i, 1, N + 1){
        mint tmp = f[N - i];
        tmp *= invfact[i];
        tmp *= ((mint)(N - i)).pow(i - 1);
        tmp *= i;
        tmp *= i;
        ans += tmp;
    }
    ans *= fact[N];
    ans *= K;
    cout << ans.val() << "\n";
}
/*
 * C[i] = a であるような i が K 個あるとする。
 * 被りなし (N - K)^{K}
 * 1 つ被り (N - K)^{K - 1} K^{2}
 * 思ったより簡単だった。。、
 */