#include <iostream>
#include <cstring>
#include <algorithm>
#define int long long
using namespace std;
int a,b,p;

signed main()
{
    cin>>a>>b>>p;

    int res = 0;
    while(b)
    {
        if(b&1)res = (res + a)%p;
        b >>= 1;
        a = (a + a)%p;
    }
    cout<<res<<endl;
    return 0;
}