#include<bits/stdc++.h>
using namespace std;
int n;
double a,b;
int main(){
    cin>>n;
    a=n/10;
    b=n%10;
    cout<<fixed<<setprecision(1)<<a/b;
	return 0;       
}
/**************************************************************
	Problem: 1607
	User: zhangziang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/