#include <stdio.h>

void main(){
	int a[100][100],b[100][100];
	int i,j,n,m,c=0;
	scanf("%d %d",&n,&m);

	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			scanf("%d",&a[i][j]);
		}
	}

	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			scanf("%d",&b[i][j]);
		}
	}

	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			if(a[i][j]==b[i][j]){
				c++;
			}
		}
	}

	printf("%.2f",c*100.0/(n*m));
}
/**************************************************************
	Problem: 1407
	User: admin
	Language: C
	Result: Accepted
	Time:21 ms
	Memory:1144 kb
****************************************************************/