#include <stdio.h>

int main(void) {
	unsigned long long int n,g,v;
	double r;
	scanf("%llu%llu%llu",&n,&g,&v);
	n/=5;
	n*=g;
	r = n;
	r/=v;
	printf("%.20lf\n",r);
	return 0;
}