#include<bits/stdc++.h>
using namespace std;
int a[10],n;
double k;
void fj(int x){
	int y=0;
	while(x!=0){
		y++;
		a[y]=x%10;
		x=x/10;
	}
	return;
}
int main(){
	cin>>n;
	fj(n);
	k=a[2]/1.0/a[1];
	cout<<fixed<<setprecision(1)<<k;
	return 0;
}jytej