```cpp
#include <bits/stdc++.h>
using namespace std;
#define LL long long
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
long long a , b , p , res;
int main()
{
    cin >> a >> b >> p;
    while ( b )
    {
        if ( b & 1 ) 
		{
			res = ( res + a ) % p;
		}
        b = b / 2; 
        a = ( a * 2 ) % p;
    }
    cout << res;
}
//菜鸟驿站
//老六专属