#include <iostream>


using namespace std;
int main(void){
    long long A,B,C;
    cin >> A >> B >> C;
    long long low = 1;
    long long high = 1000000000000000000;
    long long mid = 500000000000000000;
    
    if(A == 1)
    {
  
    while(low < high)
    {
        if(B * mid >= C)
        {
        high = mid;
        }
        else
        {
        low = mid + 1;
        }
    mid = (high + low) >> 1;
    }
    cout << low << endl;
    }
    else
    {
    long long tempB = (0x1111111100000000 & B);
    while(low < high)
    {
        long long block = mid / A;
        long long Anum = mid - block;
        
        if((tempB > 0  && (0x1111111100000 & block) > 0) || (Anum + block * B >= C))
        {
        high = mid;
        }
        else
        {
        low = mid + 1;
        }
    mid = (high + low) >> 1;
    }
    cout << low << endl;
    }
}