#include<bits/stdc++.h>
using namespace std;               
int n,a[999][999],b[999][999],c,m;
int main(){
	cin>>n>>m;
for(int i=1;i<=n;i++){
	for(int j=1;j<=m;j++){
		cin>>a[i][j];
		
	}	
}

	
		for(int i=1;i<=n;i++){
	for(int j=1;j<=m;j++){
		cin>>b[i][j];
		
		}
		
	}
		for(int i=1;i<=n;i++){
	for(int j=1;j<=m;j++){
		if(a[i][j]==b[i][j])c++;
	 }
	}	
				
printf("%.2f",c*100.0/(n*m));
}
/**************************************************************
	Problem: 1407
	User: chenxuanyi
	Language: C++
	Result: Accepted
	Time:19 ms
	Memory:9872 kb
****************************************************************/