48 人解决，66 人已尝试。
58 份提交通过，共有 197 份提交。
4.3 EMB 奖励。
单点时限: 2.0 sec
内存限制: 256 MB
Ugly numbers are numbers whose only prime factors are 2, 3 or 5. The sequence
shows the first ugly numbers. By convention, 1 is included.
Write a program to find and print the 1500’th ugly number.
The 1500'th ugly number is <number>.