#include<bits/stdc++.h> using namespace std; long long h,w,mod=998244353; long long qpow(long long k){ long long ans=1,a=2; while(k){ if(k%2)ans=(ansa)%mod; a=(aa)%mod; k/=2; } return ans; } int main(){ cin>>h>>w; cout<<qpow(((h%(mod-1))*(w%(mod-1)))%(mod-1))%mod; }

要用快速幂

用快速幂，算时写的函数要按提示写：(h%(mod-1))*(w%(mod-1)) 不然有个点过不了参考代码如下 INCLUDE <BITS/STDC++.H> using namespace std; long long h,w,ans,mod=998244353; long long quick_pow(long long a,long long b) { long long sum=1; for(;b;b>>=1){ if(b&1) sum=(suma)%mod; a=(aa)%mod; } return sum%mod; } int main() { scanf("%lld%lld",&h,&w); ans=quick_pow(2,(h%(mod-1))*(w%(mod-1))); cout<<ans; }