#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,a[105][105],b[105][105],i,j;
	float h=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]){
				h++;
			}
				
		}
	}
	h=h*100.0/(n*m);
	printf("%.2f",h);
	return 0;
}

/**************************************************************
	Problem: 1407
	User: cyp
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2076 kb
****************************************************************/