#include <stdio.h>
typedef long long int ll;
int main()
{
  int N,G,V;
  scanf("%d %d %d",&N,&G,&V);

  ll n = N;
  ll g = G;
  ll v = V;
  printf("%lf\n",(double)((n/5)*g)/(double)v);
  return 0;
}