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UKSPC Practice Problems » Ugly Numbers

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 1000th element in this sequence. There is no input to this program. Output should consist of a single line as shown below, with <number> replaced by the number computed.

Sample Output

The 1000th ugly number is <number>.