#include<iostream>
using namespace std;
typedef unsigned long long int ll;

static const ll INF=1e18+1;

ll A,B,C;

bool enough(ll x){
    ll res=(x/A)*B+(x-x/A);
    if(res>=C) return true;
    else return false;
}

int main(){
    cin >> A >> B >> C;
    ll left=0;
    ll right=C;
    while(right-left>1){
        ll mid=(left+right)/2;
        if(enough(mid)==true){
            right=mid;
        }else{
            left=mid;
        }
    }
    cout << right << endl;
}