#include <queue>
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <set>
#define ll long long
using namespace std;
int a[
3]={
2,
3,
5};
int main() {
priority_queue<ll ,
vector<ll>, greater<ll> > pq;
set<ll> s;
pq.push(
1);
s.insert(
1);
for(
int i=
1;;i++) {
if(
1500==i) {
printf(
"The 1500'th ugly number is %lld.\n",pq.top());
break;
}
else {
ll t=pq.top();pq.pop();
for(
int j=
0;j<
3;j++) {
ll num=a[j]*t;
if(!s.count(num)) {
s.insert(num);
pq.push(num);
}
}
}
}
return 0;
}
