#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,m,s = 0,s1 = 0;
    cin>>n>>m;
    int a[105][105]={0};
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            cin>>a[i][j];
        }
    }
    int b[105][105]={0};
    for(int i = 0;i<n;i++)
    {
        for(int j = 0;j<m;j++)
        {
            cin>>b[i][j];
        }
    }
    for(int i = 0;i<n;i++)
    {
        for(int j = 0;j<m;j++)
        {
            if(a[i][j] == b[i][j])
            {
                s++;
            }
        }
    }
    s1 = n*m;
    printf("%.2f",(s*1.0/s1)*100);
}

/**************************************************************
	Problem: 1407
	User: wuyichen
	Language: C++
	Result: Accepted
	Time:22 ms
	Memory:2076 kb
****************************************************************/