#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0;i<n;++i)
#define FOR(i,a,b) for(int i=a;i<b;++i)
#define RFOR(i,a,b) for(int i=b-1;i>=a;--i)
#define ALL(x) (x).begin(), (x).end()

#define ull unsigned long long
#define ll long long


signed main(void){
	cout << fixed << setprecision(15);
	double N,G,V; cin >> N >> G >> V;
	int count = (N/5);
	printf("%.15lf\n", (count*G)/V);
	return 0;
}