#include<bits/stdc++.h>
using namespace std;
int main(){
int n,m,p,ans=0,a[110];
cin>>n>>m;
for (int i = 0; i < M; i++)
{
    int p;
    cin>>p;
    a[p]=1;
}
for (int i = 0; i < N; i++)
{
    if (a[i] == 0){
        ans++;
        cout << i << " ";
    }
}

if (ans == 0)
   	cout << N;
return 0;
}

有没有大佬help me look look???