#include<bits/stdc++.h>
using namespace std;
int n,a[20][20],b[20][20],m,k;

int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>a[i][j];	
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>b[i][j];	
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			if(a[i][j]==b[i][j])k++;
			
			
		}
	}
printf("%.2f",k*1.0/(n*m)*1.0*100);
	return 0;
}

/**************************************************************
	Problem: 1407
	User: wuzihang
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2080 kb
****************************************************************/