#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    ll n, m;
    cin >> n >> m;
    deque<ll> card(n);
    rep(i, n) card[i] = i + 1;
    rep(i, m) {
        ll a;
        cin >> a;
        ll t = card[a - 1];
        for(auto it = card.begin(); it != card.end(); ) {
            if (*it == t) {
                card.erase(it);
                break;
            }
            else {
                it++;
            }
        }
        card.push_front(t);
    }
    cout << card[0] << endl;
    return 0;
}