#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    ll a,b,c;
    cin>>a>>b>>c;
    ll l=0;
    ll r=1e18+1;
    while (r-l>1) {
        ll m=(l+r)/2;
        ll sum=m/a*b+m-m/a;
        if (sum<c) l=m;
        else r=m;
    }
    cout<<r<<endl;
    return 0;
}