#include <stdio.h>

int n, used[256], v[512], cnt, ok = 0;

int main()
{
	freopen("culori.in","r",stdin);
	freopen("culori.out","w",stdout);
	
	int i;
	
	scanf("%d", &n);
	
	for(i = 1; i <= 2 * n - 1; ++i)
	{
		scanf("%d", &v[i]);
		if(!used[v[i]])
		{
			++cnt;
			used[v[i]] = 1;
		}
		if(v[i] == v[i - 1])
			ok = 1;
	}
	
	if(cnt == n)
	{
		if(!ok)
		{
			printf("1\n");
		}
		else
		{
			printf("0\n");
		}
	}
	else
	{
		printf("0\n");
	}
	
	return 0;
}