package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	N := nextInt()
	M := nextInt()

	pos := N
	for i := 1; i <= M; i++ {
		P := nextInt()
		Q := nextInt()
		switch pos {
		case P:
			pos = Q
		case Q:
			pos = P
		}
	}

	fmt.Println(pos)
}

var sc = bufio.NewScanner(os.Stdin)

func next() string {
	sc.Split(bufio.ScanWords)
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	i, e := strconv.Atoi(next())
	if e != nil {
		panic(e)
	}
	return i
}