package main
import "fmt"

func main() {
	S := 0
	fmt.Scan(&S)

	N := 0
	fmt.Scan(&N)

	for i := 0; i < N; i++ {
		var A, B int
		fmt.Scanf("%d %d", &A, &B)
		if S == A {
			S = B
		}else if S == B {
			S = A
		}
	}
	fmt.Println(S)
}