#include<bits/stdc++.h>
using namespace std;
int main(){
	int a[220][220]={0},b[220][220]={0},n,m,i,j,c=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]){
				c++;
			}
		}
	}
	printf("%.2f",c*100/1.0/n/m);	
}
/**************************************************************
	Problem: 1407
	User: lvrenxiang
	Language: C++
	Result: Accepted
	Time:19 ms
	Memory:2332 kb
****************************************************************/