#include <iostream>
#include <cstring>
using namespace std;
int main()
{
int n, m;
cin >> n >> m;
bool a[n] = {}, f = 0;
for (int i = 0; i < m; i++)
{
int t;
cin >> t;
a[t] = 1;
}
for (int i = 0; i < n; i++)
{
if (!a[i])
{
cout << i << " ";
f = 1;
}
}
if (!f)
{
cout << "N" << endl;
}
return 0;
}
result: WA