// g++-14 1.cpp -std=c++20 -O2 -I . #include using namespace std; #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") // #include // #include // #include // using namespace __gnu_pbds; #include #include using namespace atcoder; using ll = long long; using ld = long double; using vi = vector; using vvi = vector; using vll = vector; using vvll = vector; using vld = vector; using vvld = vector; using vst = vector; using vvst = vector; #define fi first #define se second #define pb push_back #define eb emplace_back #define pq_big(T) priority_queue,less> #define pq_small(T) priority_queue,greater> #define all(a) a.begin(),a.end() #define rep(i,start,end) for(ll i=start;i<(ll)(end);i++) #define per(i,start,end) for(ll i=start;i>=(ll)(end);i--) #define uniq(a) sort(all(a));a.erase(unique(all(a)),a.end()) random_device seed; mt19937_64 randint(seed()); ll grr(ll mi, ll ma) { // [mi, ma) return mi + randint() % (ma - mi); } using mint = modint998244353; constexpr ll mod = 998244353; int main(){ std::ios::sync_with_stdio(false); std::cin.tie(nullptr); ll h,w;cin>>h>>w; mint a=pow_mod(2,h,mod),b=pow_mod(2,w,mod),c=inv_mod(2,mod),d=pow_mod(2,h*w,mod),e=pow_mod(2,1,mod); // mint tar; // ll t;cin>>t; // tar=t; // rep(i,-5,5){ // rep(j,-5,5){ // rep(k,-5,5){ // rep(l,-5,5){ // rep(m,-5,5){ // rep(n,-5,5){ // mint z=a.pow(mod-1+i)*b.pow(mod-1+j)*c.pow(mod-1+k)*d.pow(mod-1+l)*e.pow(mod-1+m)+n; // if(z==tar){ // cout<