include

using namespace std; const int N = 55; int a[N << 1][N];

int main() {

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

}