题解

#include<iostream>
#include<vector>
using namespace std;
#define int long long
#define Main signed
vector<bool>a(10000010,false);
Main main(){
    ios::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
    int n;cin>>n;
    for (int i=1;i<=n;i++){
        for (int j=i;j<=n;j+=i){
            a[j]=!a[j];
        }
    }
    for (int i=1;i<=n;i++){
        if (a[i]) cout<<i<<' ';
    }
    return 0;
}