CF962C.Make a Square

普及/提高-

通过率：0%

AC君温馨提醒

该题目为【codeforces】题库的题目，您提交的代码将被提交至codeforces进行远程评测，并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供，我们无法保证该服务的稳定性，若提交后无反应，请等待一段时间后再进行重试。

题目描述

You are given a positive integer $n$ , written without leading zeroes (for example, the number 04 is incorrect).

In one operation you can delete any digit of the given integer so that the result remains a positive integer without leading zeros.

Determine the minimum number of operations that you need to consistently apply to the given integer $n$ to make from it the square of some positive integer or report that it is impossible.

An integer $x$ is the square of some positive integer if and only if $x=y^2$ for some positive integer $y$ .

输入格式

The first line contains a single integer $n$ ( $1 \le n \le 2 \cdot 10^{9}$ ). The number is given without leading zeroes.

输出格式

If it is impossible to make the square of some positive integer from $n$ , print -1. In the other case, print the minimal number of operations required to do it.

输入输出样例

输入#1
```
8314
```
输出#1
```
2
```
输入#2
```
625
```
输出#2
```
0
```
输入#3
```
333
```
输出#3
```
-1
```

说明/提示

In the first example we should delete from $8314$ the digits $3$ and $4$ . After that $8314$ become equals to $81$ , which is the square of the integer $9$ .

In the second example the given $625$ is the square of the integer $25$ , so you should not delete anything.

In the third example it is impossible to make the square from $333$ , so the answer is -1.

首页