#include<iostream>
using namespace std;
bool isugly(int num){ //13也是丑数
while(num!=0){
if(num==1)
return 1;
else if(num%2==0)
num/=2;
else if(num%3==0)
num/=3;
else if(num%5==0)
num/=5;
else
return 0;
}
}
int finduglynumber(int n){
int b[500],j=1;
if(n<1||n>500)return -1;
for(int i=1;i<=500;i++)
if(isugly(i))
b[j++]=i;
return b[n];
}
void main(){
int n;
cin>>n;
while(n){
cout<<finduglynumber(n)<<endl;
cin>>n;
}
}