//#define USEPB_DS
#define USETR1
#define CPPELEVEN
#define GPP

/*
 * temp.cpp
 *
 *  Created on: 2012-7-18
 *      Author: BSBandme
 */
//#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <bits/stdc++.h>

using namespace std;

#ifndef CPPELEVEN
#ifdef USETR1
#include <tr1/unordered_map>
#include <tr1/unordered_set>
using namespace tr1;
#endif
#else
#include <unordered_map>
#include <unordered_set>
#endif

#ifdef USEPB_DS
#include <ext/pb_ds/priority_queue.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
// binomial_heap_tag, rc_binomial_heap_tag, thin_heap_tag, binary_heap_tag
typedef __gnu_pbds::priority_queue<int, greater<int>, pairing_heap_tag> pq_type;
// splay_tree_tag, ov_tree_tag
typedef tree <int, null_type, less <int>, rb_tree_tag, tree_order_statistics_node_update> tree_type;
#endif

#define mpr make_pair
typedef unsigned int ui;
typedef unsigned long long ull;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef pair <double, double> pdd;
typedef vector <int> vi;
typedef vector <ll> vll;
typedef vector <double> vd;
typedef vector <string> vs;
typedef map <string, int> mpsi;
typedef map <double, int> mpdi;
typedef map <int, int> mpii;

const double pi = acos(0.0) * 2.0;
const long double eps = 1e-10;
const int step[8][2] = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}, {-1, 1}, {1, 1}, {1, -1}, {-1, -1}};

template <class T> inline T abs1(T a) {return a < 0 ? -a : a;}

#ifndef CPPELEVEN
template <class T> inline T max1(T a, T b) { return b < a ? a : b; }
template <class T> inline T max1(T a, T b, T c) { return max1(max1(a, b), c); }
template <class T> inline T max1(T a, T b, T c, T d) { return max1(max1(a, b, c), d); }
template <class T> inline T max1(T a, T b, T c, T d, T e) { return max1(max1(a, b, c, d), e); }
template <class T> inline T min1(T a, T b) { return a < b ? a : b; }
template <class T> inline T min1(T a, T b, T c) { return min1(min1(a, b), c); }
template <class T> inline T min1(T a, T b, T c, T d) { return min1(min1(a, b, c), d); }
template <class T> inline T min1(T a, T b, T c, T d, T e) { return min1(min1(a, b, c, d), e); }
#else
template <typename t, typename t1>
t min1(t a, t1 b) { return a < b ? a : b; }
template <typename t, typename... arg>
t min1(t a, arg... arr) { return min1(a, min1(arr...)); }
template <typename t, typename t1>
t max1(t a, t1 b) { return a > b ? a : b; }
template <typename t, typename... arg>
t max1(t a, arg... arr) { return max1(a, max1(arr...)); }
#endif

inline int jud(double a, double b){
  if(abs(a) < eps && abs(b) < eps) return 0;
  else if(abs1(a - b) / max(abs1(a), abs1(b)) < eps) return 0;
  if(a < b) return -1;
  return 1;
}
template <typename t> inline int jud(t a, t b){
  if(a < b) return -1;
  if(a == b) return 0;
  return 1;
}

// f_lb == 1代表返回相同的一串的左边界，f_small == 1代表返回如果没有寻找的值返回小的数
template <typename it, typename t1>
inline int find(t1 val, it a, int na, bool f_small = 1, bool f_lb = 1){
  if(na == 0) return 0;
  int be = 0, en = na - 1;
  if(*a <= *(a + na - 1)){
    if(f_lb == 0) while(be < en){
      int mid = (be + en + 1) / 2;
      if(jud(*(a + mid), val) != 1) be = mid;
      else en = mid - 1;
    }else while(be < en){
      int mid = (be + en) / 2;
      if(jud(*(a + mid), val) != -1) en = mid;
      else be = mid + 1;
    }
    if(f_small && jud(*(a + be), val) == 1) be--;
    if(!f_small && jud(*(a + be), val) == -1) be++;
  } else {
    if(f_lb) while(be < en){
      int mid = (be + en + 1) / 2;
      if(jud(*(a + mid), val) != -1) be = mid;
      else en = mid - 1;
    }else while(be < en){
      int mid = (be + en) / 2;
      if(jud(*(a + mid), val) != 1) en = mid;
      else be = mid + 1;
    }
    if(!f_small && jud(*(a + be), val) == -1) be--;
    if(f_small && jud(*(a + be), val) == 1) be++;
  }
  return be;
}

template <class T> inline T lowb(T num) {return num & (-num); }
#ifdef GPP
inline int bitnum(ui nValue) { return __builtin_popcount(nValue); }
inline int bitnum(int nValue) { return __builtin_popcount(nValue); }
inline int bitnum(ull nValue) { return __builtin_popcount(nValue) + __builtin_popcount(nValue >> 32); }
inline int bitnum(ll nValue) { return __builtin_popcount(nValue) + __builtin_popcount(nValue >> 32); }
inline int bitmaxl(ui a) { if(a == 0) return 0; return 32 - __builtin_clz(a); }
inline int bitmaxl(int a) { if(a == 0) return 0; return 32 - __builtin_clz(a); }
inline int bitmaxl(ull a) { int temp = a >> 32; if(temp) return 32 - __builtin_clz(temp) + 32; return bitmaxl(int(a)); }
inline int bitmaxl(ll a) { int temp = a >> 32; if(temp) return 32 - __builtin_clz(temp) + 32; return bitmaxl(int(a)); }
#else
#endif

long long pow(long long n, long long m, long long mod = 0){
  if(m < 0) return 0;
  long long ans = 1;
  long long k = n;
  while(m){
    if(m & 1) {
      ans *= k;
      if(mod) ans %= mod;
    }
    k *= k;
    if(mod) k %= mod;
    m >>= 1;
  }
  return ans;
}

#define  MOD 1000000007
template <class t1, class t2>
inline void add(t1 &a, t2 b, int mod = -1) {
  if(mod == -1) mod = MOD;
  a += b;
  while(a >= mod) a -= mod;
  while(a < 0) a += mod;
}
template <class t>
void output1(t arr) {
  for(int i = 0; i < (int)arr.size(); i++)
    cerr << arr[i] << ' ';
  cerr << endl;
}
template <class t>
void output2(t arr) {
  for(int i = 0; i < (int)arr.size(); i++)
    output1(arr[i]);
}

//....................密..........封..........线..........下..........禁..........止..........hack...............................................

const int maxn = 500100;
const int mod = 998244353;
int n, m;
ll fac[maxn], invfac[maxn];

ll c(int a, int b) {
  if (a < b) return 0;
  return fac[a] * invfac[b] % mod * invfac[a - b] % mod;
}

int main() {
  //............................不要再忘了检查maxn大小了！！！！BSBandme你个SB！！！！........................................
  ios_base::sync_with_stdio(0);
  #ifdef DEBUG //......................................................................................................
  freopen("input.txt", "r", stdin);
  #endif //...........................................................................................................

  scanf("%d%d", &n, &m);
  if (n > m) swap(n, m);
  fac[0] = 1;
  for (int i = 1; i < maxn; i++) fac[i] = fac[i - 1] * i % mod;
  invfac[maxn - 1] = pow(fac[maxn - 1], mod - 2, mod);
  for (int i = maxn - 1; i > 0; i--) invfac[i - 1] = invfac[i] * i % mod;
  ll ans = 0;
  for (int i = 0; i <= n; i++) {
    ll f = bool((i + 1) % 2) * 2 - 1;
    ans += f * c(n, i) % mod * c(m, i) % mod * fac[i] % mod * pow(m + 1, n - i, mod) % mod * pow(n + 1, m - i, mod) % mod;
    ans %= mod;
  }
  cout << (ans + mod) % mod << endl;

  return 0;
}


Measured memory_bytes: 8064