#include<stdio.h>
#include<float.h>

int main(void){
	float n,g,v,t,t1;
	//int t;

	scanf("%f",&n);
	scanf("%f",&g);
	scanf("%f",&v);

	t = n/5;

	t1 = t*g;

	printf("%f",t1/v);

	return 0;
}