Testing Round 15 (Unrated)


A. Digits Sequence (Easy Edition)
time limit per test: 1 second
memory limit per test: 256 megabytes
input: standard input
output: standard output

Examples
Input
7
Output
7
Input
21
Output
5
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B. Digits Sequence (Hard Edition)
time limit per test: 1 second
memory limit per test: 256 megabytes
input: standard input
output: standard output

Examples
Input
7
Output
7
Input
21
Output
5
----------------------------------------------------------------------------------------------------
