package main

import (
	"fmt"
)

func resolve(N, M int, A []int) int {
	B := make([]int, N)
	for i := 0; i < N; i++ {
		B[i] = i + 1
	}

	for i := 0; i < M; i++ {
		a := A[i]
		B = append(append([]int{B[a-1]}, B[:a-1]...), B[a:]...)
	}
	return B[0]
}

func main() {
	var N, M int

	fmt.Scanf("%d", &N)
	fmt.Scanf("%d\n", &M)

	A := make([]int, M)
	for i := 0; i < M; i++ {
		fmt.Scanf("%d", &A[i])
	}
	fmt.Scanf("\n")

	fmt.Println(resolve(N, M, A))
}