include

using namespace std; int a[105] [55];

int main() {

int n, m;
cin >> n >> m;
int ans = 0;
for (int i = 1; i <= n * 2; 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++ )
		if (a[i][j] == a[n + i][j])
			ans++;
}
cout << ans;
return 0;

}