#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
int cmp(const void *a,const void *b){
    if(*(int*)a>*(int*)b){return 1;}
    else if(*(int*)a<*(int*)b){return -1;}
    else {return 0;}
}
int min(int a,int b){

    if(a>=b){return b;}
    return a;
}
//cww
int main(void){
long long int n,g,v,ye;
double ans;
scanf("%lld %lld %lld",&n,&g,&v);
n=n/5;
ye=n*g;
ans=(double)ye/v;
printf("%.12lf",ans);
}