#include<bits/stdc++.h>
using namespace std;
int main(){
	int a[100][100]={0},b[100][100]={0},n,m,i,j,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];
		}
	}
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			if(a[i][j]==b[i][j]) h++; 
		}
	}
	printf("%.2f",h/(n*m*1.0)*100);
}
/**************************************************************
	Problem: 1407
	User: linzihang
	Language: C++
	Result: Accepted
	Time:22 ms
	Memory:2076 kb
****************************************************************/