#include<stdio.h>
int main()
{
	int n;
	scanf("%d", &n);
	int i;
	int s[502], t[502];
	for (i = 0; i < n; i++)
		scanf("%d", &s[i]);
	for (i = 0; i < n; i++)
		scanf("%d", &t[i]);
	long long int c1, c2;
	c1 = c2 = 0;
	for (i = 0; i < n; i++)
		if (s[i] == 2)
			c1++;
	for (i = 0; i < n; i++)
		if (t[i] == 2)
			c2++;
	int ans;
	if (c1 > 0 && c2 > 0)
		ans = n * c1 + (n - c1) * c2;
	else if (c1 > 0)
	{
		ans = n * c1;
		for (i = 0; i < n; i++)
			if (s[i] == 1)
				ans++;
	}
	else if (c2 > 0)
	{
		ans = n * c2;
		for (i = 0; i < n; i++)
			if (t[i] == 1)
				ans++;
	}
	else
	{
		c1 = c2 = 0;
		for (i = 0; i < n; i++)
			if (s[i] > 0)
				c1++;
		for (i = 0; i < n; i++)
			if (t[i] > 0)
				c2++;
		ans = c1;
		if (ans < c2)
			ans = c2;
	}
	printf("%d\n", ans);
	return 0;
}