#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>
#include<list>
#include<bitset>
#include<functional>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000
#define PI 3.14159265358979

using namespace std;
typedef pair<int, int> P;

int main(void) {
	int n, m;
	int a[100001];
	int dp[51];
	int tmp;
	int tell;

	cin >> n >> m;
	FOR(i, 1, m) {
		cin >> a[i];
	}
	FOR(i, 1, n) {
		dp[i] = i;
	}

	FOR(i, 1, m) {
		tmp = dp[a[i]];
		RFOR(t, a[i],2) {
			dp[t] = dp[t - 1];
		}
		dp[1] = tmp;
	}
	cout << dp[1] << endl;
	return 0;
}