#include <bits/stdc++.h>
using namespace std;
int main(){
	int n,m,a[100][100]={0},i,j,b[100][100]={0};
	float h=0;
	cin>>n>>m;
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			cin>>a[i][j];
		}
	}
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			cin>>b[i][j];
			if(a[i][j]==b[i][j]){
				h++;
			}
		}
	}
	h=h/(m*n)*100.0;
	printf("%.2f",h);


}
/**************************************************************
	Problem: 1407
	User: jiangyuanfeng
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2076 kb
****************************************************************/