#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <list>
#include <functional>
#include <queue>
#include <map>
#include <iterator>
#include <iomanip>
#include <complex>
using namespace std;

using ull = unsigned long long;
using ll = long long;


int main()
{
  int n,m;
  cin >> n >> m;
  list<int> cards(n);

  int count = 1;
  for(auto&& x : cards)
  {
    x = count;
    ++count;
  }

  for(int i = 0; i < m; ++i)
  {
    int x;
    cin >> x;
    x--;
    auto itr = next(cards.begin(),x);
    cards.erase(itr);
    cards.push_front(*itr);
  }

  cout << *cards.begin() << endl;


}