package main

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

func main() {
	var n, m int
	var s string
	cards := make([]int, 0, 50)

	fmt.Scanln(&n, &m)
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	s = scanner.Text()

	for i := 1; i <= n; i++ {
		cards = append(cards, i)
	}

	for _, v := range strings.Split(s, " ") {
		i, _ := strconv.Atoi(v)
		j := i - 1
		tmp := append([]int{cards[j]}, cards[:j]...)
		cards = append(tmp, cards[j+1:]...)
	}

	fmt.Println(cards[0])
}