#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,g,s;
    double ans;
    cin>>n;
    s=n/10%10;
    g=n%10;
    ans=s*1.0/g;
    printf("%.1f",ans);
     
}
/**************************************************************
	Problem: 1607
	User: chenjiahui
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/