#include <bits/stdc++.h>
#define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false))
#define precise(i) fixed << setprecision(i)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;

int main() {
  fastIO;
  int n, m;
  cin >> n >> m;
  vector<int> cards(n);
  for (int i = 0; i < n; i++) {
    cards[i] = i + 1;
  }

  // input
  for (int i = 0, num; i < m; i++) {
    cin >> num;
    num--;

    vector<int> nums;
    nums.emplace_back(cards[num]);
    for (size_t i = 0; i < cards.size(); i++) {
      if (i != num) nums.emplace_back(cards[i]);
    }
    cards = nums;
  }

  cout << cards.front() << '\n';

  return 0;
}