package main

import (
	"fmt"
)

func resolve(N, M int, P, Q []int) int {
	ret := N
	for i := 0; i < M; i++ {
		switch {
		case P[i] == ret:
			ret = Q[i]
		case Q[i] == ret:
			ret = P[i]
		}
	}
	return ret
}

func main() {
	var N, M int
	fmt.Scanf("%d\n%d\n", &N, &M)
	P := make([]int, M)
	Q := make([]int, M)
	for i := 0; i < M; i++ {
		fmt.Scanf("%d %d\n", &P[i], &Q[i])
	}
	fmt.Println(resolve(N, M, P, Q))
}