#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
//#include <atcoder/all>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
using ll = long long;
using namespace std;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}

int main(){
  int N,M; cin >> N >> M;
  vector<int> A(M); rep(i,M) cin >> A[i];
  vector<int> C(N);
  rep(i,N) C[i]=i+1;
  rep(i,M){
    int a = A[i]-1;
    vector<int> B(M);
    B[0]=C[a];
    int idx=1;
    rep(j,M){
      if(j==a) continue;
      B[idx]=C[j];
      idx++;
    }
    C = B;
  }
  cout << C[0] << endl;
  return 0;
}