#include "bits/stdc++.h"
using namespace std;
using Graph = vector<vector<int>>;
typedef long long ll;
typedef pair<ll, ll> P;
#define rep(i,n) for (ll i = 0; i < (n); ++i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const long long mod = 1e9 + 7;

ll gcd(ll a, ll b) {
	return b ? gcd(b, a % b) : a;
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

int main() {
	ll n, m;
	cin >> n >> m;
	
	deque<ll> d;

	for (ll i = 1; i <= n; i++) {
		d.push_back(i);
	}

	rep(i, m) {
		ll a;
		cin >> a;
		a--;
		ll num = d[a];
		d.erase(d.begin()+a);
		d.push_front(num);
	}
	
	cout << d[0] << endl;
}