#include<bits/stdc++.h>
using namespace std;
int main(){
	int m;
	float a,b,c;
	scanf("%d",&m);
	a=m%10;
	b=m/10%10;
	c=b/a;
	printf("%.1f",c);
	return 0;
}
/**************************************************************
	Problem: 1607
	User: toughuatao1
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/