#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    float s=0,g=0,h=0;
	cin>>n;
	s=n%10;
	g=n/10;
	h=g/s;
	printf("%.1lf",h);
}
/**************************************************************
	Problem: 1607
	User: huxuanchen
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/