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