#include #define rep(i,n) for(int i = 0; i < (n); ++i) #define srep(i,s,t) for (int i = s; i < t; ++i) #define drep(i,n) for(int i = (n)-1; i >= 0; --i) using namespace std; typedef long long int ll; typedef pair P; #define yn {puts("Yes");}else{puts("No");} #define MAX_N 200005 int main() { int n, g, v; cin >> n >> g >> v; int x = (n / 5) * g; double ans = (double)x / v; cout << fixed << setprecision(10) << ans << endl; return 0; }