#include <bits/stdc++.h>
#define ALL(v) begin(v), end(v)

using i64 = int64_t;

const int kMod = 998244353;
auto Power(int a, int b, int p = kMod) {
  int r = 1;
  for (; b; b >>= 1, a = i64{a} * a % p) {
    if (b & 1) r = i64{r} * a % p;
  }
  return r;
}

int n, m;

auto main() -> int {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr), std::cout.tie(nullptr);

  std::cin >> n >> m;
  std::cout << i64{Power(n, m - 1)} * Power(m, n - 1) % kMod << '\n';

  return 0;
}