Square Prime

#include<stdio.h>
#include<vector>
typedef long long int ll;
using namespace std;

bool sieve[1000010];
int main()
{
    vector<ll> vec;
    int cnt = 0;
    for(ll i = 2 ; i <= 1000000 ; i ++){
        if(!sieve[i]){
            vec.push_back(i*i);
            for(ll j = i*2; j <= 1000000 ; j += i){
                sieve[j] = true;
            }
            cnt++;
        }

    }
    ll L,R;
    scanf("%lld %lld",&L,&R);
    bool check = false;
    for(int i = 0 ; i < vec.size() ; i ++){
        if(L <= vec[i] && vec[i] <= R){
            printf("%lld ",vec[i]);
            check = true;
        }
    }
    if(!check)printf("-1");
    return 0;
}