package main

import (
	"fmt"
	"io"
	"os"
)

func main() {
	buf, _ := io.ReadAll(os.Stdin)
	var pos int

	readInt := func() int {
		for pos < len(buf) && buf[pos] <= ' ' {
			pos++
		}
		if pos >= len(buf) {
			return 0
		}
		res := 0
		for pos < len(buf) && buf[pos] > ' ' {
			res = res*10 + int(buf[pos]-'0')
			pos++
		}
		return res
	}

	n := readInt()
	k := readInt()
	if n == 0 {
		return
	}

	a := make([]int, 0, n)
	for i := 0; i < n; i++ {
		v := readInt()
		if len(a) == 0 || a[len(a)-1] != v {
			a = append(a, v)
		}
	}

	m := len(a)
	saved := make([]int, k+1)

	for i := 0; i < m; i++ {
		if i > 0 && i < m-1 {
			if a[i-1] == a[i+1] {
				saved[a[i]] += 2
			} else {
				saved[a[i]] += 1
			}
		} else {
			saved[a[i]] += 1
		}
	}

	maxSaved := -1
	bestGenre := -1

	for i := 1; i <= k; i++ {
		if saved[i] > maxSaved {
			maxSaved = saved[i]
			bestGenre = i
		}
	}

	fmt.Println(bestGenre)
}