package main

import (
	"fmt"
)

func main() {
	var N, M, s, d int
	_, _ = fmt.Scan(&N, &M)
	for i := 0; i < M; i++ {
		_, _ = fmt.Scan(&s, &d)
		if s == N {
			N = d
		} else if d == N {
			N = d
		}
	}
	fmt.Println(N)
}