#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef pair<int,int> P;
typedef unsigned long long ul;

ul a, b , c;

bool ok(ul d) {
  ul sum = d / a * b + d - d / a;
  return sum >= c;
}

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