UVa 136 Ugly Numbers(数論)

136 - Ugly Numbers
Time limit: 3.000 seconds
http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=72
Ugly numbers are numbers whose only prime factors are 2, 3 or 5. The sequence
1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, ...
shows the first 11 ugly numbers. By convention, 1 is included.
Write a program to find and print the 1500'th ugly number.
Input and Output
There is no input to this program. Output should consist of a single line as shown below, with replaced by the number computed.
Sample output
The 1500'th ugly number is .
暴力で答えを先に計算することができます.
あるいは、2,3,5でパッチワークします.
完全なコード:

/*0.009s*/

#include <cstdio>

int main(void)
{
	puts("The 1500'th ugly number is 859963392.");
	return 0;
}