#include<bits/stdc++.h> using namespace std; int n; vector<int> prime; bool isPrime(int x){ if(x==1)return 0; for(int i=2;i<=x/i;i++)if(x%i==0)return 0; return 1; } int main(){ cin>>n; for(int i=1;i<=n;i++){ int a; cin>>a; if(isPrime(a)) prime.push_back(a); } cout<<prime.size()<<endl; for(int i=0;i<prime.size();i++)cout<<prime[i]<<endl; return 0; }