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

#define rep(i,j,n) for(int i=j;i<n;++i)
#define all(i) i.begin(),i.end()
#define rall(i) i.rbegin(), i.rend()
#define INF 1e9
#define LINF 1e18
const int mod = 1e9 + 7;

typedef long long i64;
typedef pair<int, int> pi;

template <class T> using vt = vector<T>;
template <class T> using vvt = vector<vector<T>>;

i64 gcd(i64 n, i64 m) {return (m == 0? n : gcd(m, n % m));}
i64 lcd(i64 n, i64 m) {return (n / gcd(n, m) * m);}
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

i64 a, b, c;

bool check(i64 m) {
  i64 t = b * (m / a) + m - (m / a);
  return t >= c;
}

i64 binary_search() {
  i64 ng = 0, ok = c;

  while(abs(ok - ng) > 1) {
    i64 mid = ng + (ok - ng) / 2;

    if(check(mid)) ok = mid;
    else ng = mid;
  }
  return ok;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> a >> b >> c;
  cout << binary_search() << endl;
}