#include <iostream>
#include <vector>

using namespace std;

int main(int argc, const char * argv[]) {
  vector<int> card;
  int n, k, i, temp;

  cin >> n >> k;

  for (i = 0; i < n; i++)
    card.push_back(i + 1);
  
  for (; k > 0; k--) {
    cin >> i;
    temp = card[--i];
    card.erase(card.begin() + i);
    card.insert(card.begin(), temp);
  }

  cout << card[0] << endl;

  return 0;
}