#include<stdio.h>
int main()
{
	int n, m;
	scanf("%d%d", &n, &m);
	int a[4];
	a[1] = a[2] = a[3] = 0;
	a[n] = 1;
	int p, q;
	int i;
	for (i = 0; i < m; i++)
	{
		scanf("%d %d", &p, &q);
		a[p] ^= a[q];
		a[q] ^= a[p];
		a[p] ^= a[q];
	}
	if (a[1] > 0)
		printf("1\n");
	else if (a[2] > 0)
		printf("2\n");
	else
		printf("3\n");
	return 0;
}