#include <bits/stdc++.h> using namespace std;

int main() { int n, m, a[100005], x; cin >> n >> m; for (int i = 1; i <= n; i++) { cin >> x; a[x]++; } for (int j = 1; j <= n; j++) { if (a[j] == 0) { cout << j << endl; } } return 0; }

#include <bits/stdc++.h> using namespace std;

int main() { int n, m, a[100005], x; cin >> n >> m; for (int i = 1; i <= n; i++) { cin >> x; a[x]++; } for (int j = 1; j <= n; j++) { if (a[j] == 0) cout << j << endl; }

return 0;

}