#include<bits/stdc++.h>
using namespace std;
int main(){
   int m,n,i,j;
   float h=0;
   cin>>m>>n;
	int a[n][m];
   	 int b[n][m];
	for(i=0;i<m;i++){
        for(j=0;j<n;j++){
            cin>>a[i][j];
        }
    }
    for(i=0;i<m;i++){
        for(j=0;j<n;j++){
            cin>>b[i][j];
        }
    }
    for(i=0;i<m;i++){
        for(j=0;j<m;j++){
            if(a[i][j]==b[i][j]){
                h++;
             }
         }
      } 
      h=h/(n*m)*100.0;
      printf("%.2f",h);
  }
/**************************************************************
	Problem: 1407
	User: wuzhijing
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2076 kb
****************************************************************/