#include<bits/stdc++.h>
using namespace std;
int main(){
	int m,n,i,j,a[100][100],b[100][100];
	float s;
	cin>>m>>n;
	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]){
				s++;
			}
		}
	}
	s=s/(n*m)*100.0;
	printf("%.2f",s);
} 
/**************************************************************
	Problem: 1407
	User: linyuhang
	Language: C++
	Result: Accepted
	Time:17 ms
	Memory:2076 kb
****************************************************************/