#include<iostream>
using namespace std;
int main(){
	long long int x;
	while(cin>>x){
		if(x>0){
			long long int y,i,j;
			for(i=1;i*i<=x;i=i+1){
				for(j=i;j*j<=x;j=j+1){
					y=i*j;
				}
			}
			cout<<y<<endl;
		}else{
			return 0;
		}
	}
}