#include <iostream> using namespace std; int main(){ int n,m; cin>>n>>m; int s[m]; bool b[n]={true}; for(int i=0;i<m;++i){ cin>>s[i]; b[s[i]-1]=false; } for(int i=0;i<n;++i){ if(b[i]==true) cout<<i+1<<" "; } return 0; }