Example

Input

5 3
4
2
5


Output

5
2
4
1
3
#include <bits/stdc++.h>
using namespace std;
#define REP(i, n) for (int i = 0; i < int(n); ++i)
#define REPE(i, a, b) for (int i = (a); i <= int(b); ++i)
#define SZ(x) ((int)(x).size())
#define ALL(x) x.begin(), x.end()
#define PB push_back
#define EB emplace_back
using LL = long long;
using PII = pair<int, int>;
#define F first
#define S second

int n, m, w[200010], a[200010];

int main() {
  int n, m;
  scanf("%d%d", &n, &m);
  REPE(i, 1, n) w[i] = i;
  REP(i, m) {
    int x;
    scanf("%d", &x);
    w[x] = -i;
  }
  REP(i, n) a[i] = i + 1;
  sort(a, a + n, [](int x, int y) { return w[x] < w[y]; });
  REP(i, n) printf("%d\n", a[i]);
  return 0;
}