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

int main(){
	int a[110][110],b[110][110];
	int n,m,i,j,c = 0;//c是计数器
	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];
		}
	}
	//求一样的点的数量 
	for(i = 0;i < n;i++){
		for(j = 0;j < m;j++){
			if(a[i][j] == b[i][j]){
				c++;
			}
		}
	}
	
	double r = c * 1.0 / (n * m) * 100;
	cout<<fixed<<setprecision(2)<<r<<endl;
	  
    return 0;
}

/**************************************************************
	Problem: 1407
	User: admin
	Language: C++
	Result: Accepted
	Time:17 ms
	Memory:2072 kb
****************************************************************/