打卡记录

#include <iostream>

using namespace std;

int main()
{
    long long a, b, p, ans;
    cin >> a >> b >> p;
    for( ; b; b>>=1)
    {
        if(b & 1) ans = (ans + a) % p;
        a = a * 2 % p;
    }
    cout << ans << endl;
}