#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a;
    float d,b,c;
    cin>>a;
    b=a/10;
    c=a%10;
    d=b/c;
    printf("%.1f",d);
    return 0;
}
/**************************************************************
	Problem: 1607
	User: fuhoubin
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/