#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,x=0,y=0;
	float j;
	cin>>n;
	x=n/10;
	y=n%10;
	j=x*1.0/y;
	printf("%.1f",j);
}
/**************************************************************
	Problem: 1607
	User: linmiaoling
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/