#include<bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(int)(n);i++)
using namespace std;
using P=pair<int,int>;

int main(){
  double x,y,z;
  cin>>x>>y>>z;
  cout<<floor((y*z-1)/x)<<endl;
}
#include <bits/stdc++.h>
using namespace std;

int main(){
    double X, Y, Z, v, a, b;
    cin >> X >> Y >> Z;
    v = Y / X;
    a = Z * v;
    long long int d = a;
    if(d == a){
        cout << d-1 << endl;
    }else{
        cout << d << endl;
    }
    return 0;
}