module main;

import std;

void main()
{
	auto N = readln.chomp.to!int;
	auto M = readln.chomp.to!int;
	auto cups = new bool[](4);
	cups[N] = true;
	foreach (_; 0 .. M) {
		int P, Q;
		readln.chomp.formattedRead("%d %d", P, Q);
		swap(cups[P], cups[Q]);
	}
	writeln(cups.countUntil(true));
}