C++ :

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
char a[100000000];
int main()
{
	int n,m,i,j,k,t=0;
	cin>>n;
	for (k=10;k<=floor(sqrt(n));k++)
	{
		m=k*k;
		sprintf(a,"%d",m);
		i=0;j=strlen(a)-1;
		while (i<j&&a[i]==a[j]) {i++;j--;}
		if (i>=j){
			t++;
			if (t==1) cout<<m;
			else cout<<" "<<m;
		}
	}
	cout<<endl;
	return 0;
}