C++ :

#include <bits/stdc++.h>
using namespace std;

int main(){
	//freopen("10.in","r",stdin);
	//freopen("10.out","w",stdout);
	string a,b;
	int l,m;
	
	//getline(cin,a);
	//getline(cin,b);
	cin>>a;
	cin>>b;
	l=a.size();
	m=0;
	for(int i=0;i<l;i++){
		if(a[i]==b[i]){
			m++;	
		}
	}
	
	printf("%.2lf",m/(l*1.0));
	//fclose(stdin);
	//fclose(stdout);
	return 0;
}