#include <bits/stdc++.h>
using namespace std;

int main() {
    int N, M;
    cin >> N >> M;
    vector<int> card(N);
    iota(card.begin(), card.end(), 1);

    while (M--) {
        int A;
        cin >> A;
        A--;

        int tmp = card[A];
        card.erase(card.begin() + A);

        card.insert(card.begin(), tmp);
    }

    cout << card[0] << endl;
}