AtCoder Beginner Contest 182
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Problem Statement
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Given is a positive integer $N$, where none of the digits is $0$.
Let $k$ be the number of digits in $N$. We want to make a multiple of $3$ by erasing at least $0$ and at most $k-1$ digits from $N$ and concatenating the remaining digits without changing the order.
Determine whether it is possible to make a multiple of $3$ in this way. If it is possible, find the minimum number of digits that must be erased to make such a number.
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Constraints
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$1 \le N \lt 10^{18}$- None of the digits in
$N$is$0$.
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Input
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Input is given from Standard Input in the following format:
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N翻译中…
Output
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If it is impossible to make a multiple of $3$, print -1; otherwise, print the minimum number of digits that must be erased to make such a number.
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样例
Input #1
35
Output #1
1
By erasing the $5$, we get the number $3$, which is a multiple of $3$. Here we erased the minimum possible number of digits - $1$.
Input #2
369
Output #2
0
Note that we can choose to erase no digit.
Input #3
6227384
Output #3
1
For example, by erasing the $8$, we get the number $622734$, which is a multiple of $3$.
Input #4
11
Output #4
-1
Note that we must erase at least $0$ and at most $k-1$ digits, where $k$ is the number of digits in $N$, so we cannot erase all the digits.
In this case, it is impossible to make a multiple of $3$ in the way described in the problem statement, so we should print `-1`.
题目信息
题面与样例版权归 AtCoder 及出题人所有；中文翻译由 AI 生成（CI 管线），如有出入请以原文为准。