#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,a[100][100]={0},v[100][100]={0},i,j;
	float s=0;
	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>>v[i][j];
		}
	}
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			if(a[i][j]==v[i][j]){
				s=s+1;
			}
		}
	}
	s=s/(n*m)*100.0;
	printf("%.2f",s);
}
/**************************************************************
	Problem: 1407
	User: huxuanchen
	Language: C++
	Result: Accepted
	Time:16 ms
	Memory:2076 kb
****************************************************************/