#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int n, m;
  cin >> n >> m;
  vector<int> a(m);
  rep(i, m) cin >> a[i];
  vector<int> ans(n);
  iota(ans.begin(), ans.end(), 1);
  rep(i, m) {
    ans.insert(ans.begin(), ans[a[i] - 1]);
    ans.erase(ans.begin() + a[i]);
    Debug(ans);
  }
  cout << ans[0] << endl;
  return 0;
}