64分求助

#include<cstdio>
#define int long long
using namespace std;
int ksm(int a,int b,int mod){
    int ans=1;
    while(b){
        if(b&1)ans=(ans*a)%mod;
        a=(a*a)%mod;
        b>>=1;
    }
    ans%=mod;
    return ans;
}
signed main(){
      int a,b,p;
      scanf("%lld%lld%lld",&a,&b,&p);
      a%=p;
      int k=ksm(a,b,p);
      printf("%lld^%lld mod %lld=%lld",a,b,p,k);
      return 0;
}