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

int main(){
  ll n,g,x;
  double m,h,v,a,y;
  cin>>n>>g>>v;
  n/=5;
  m=(double)n;

  x=n*g;
  y=(double)x;

  a=y/v;
  cout<<fixed<<setprecision(12)<<a<<endl;
  return 0;
}