Example

Input

5 3
4
2
5


Output

5
2
4
1
3
#include <bits/stdc++.h>
typedef long long LL;
#define SORT(c) sort((c).begin(),(c).end())
 
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
 
using namespace std;
int main(void)
{
  int n, m;
  cin >> n >> m;
  vector<bool> used(n+1,false);
  vector<int> rseq(n);
  REP(i,n) rseq[i]=n-i;
  REP(i,m){
    int tmp;
    cin >> tmp;
    rseq.push_back(tmp);
  }
  for(int i=n+m-1;i>=0;--i)
    if(!used[rseq[i]]){
      used[rseq[i]]=true;
      cout << rseq[i] << endl;
    }
  return 0;
}