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.

Input

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

Output

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.

Examples

Input

8314


Output

2


Input

625


Output

0


Input

333


Output

-1

Note

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.
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class Solution {

	static InputReader in = new InputReader(System.in);
	static OutputWriter out = new OutputWriter(System.out);
	static int exp = (int) (1e9);

	public static void main(String[] args) {

		int n = in.nextInt();
		String s = Integer.toString(n);
		ArrayList<Integer> sq = getSquares(n);

		for (int i = 0; i < sq.size(); i++) {
			String regex = getRegexed(Integer.toString(sq.get(i)));
			if (s.matches(regex)) {
				System.out.println(s.length() - Integer.toString(sq.get(i)).length());
				System.exit(0);
			}
		}
		System.out.println(-1);
	}

	static String getRegexed(String str) {
		String tmp = ".*";
		for (int i = 0; i < str.length(); i++) {
			tmp += str.charAt(i) + ".*";
		}
		return tmp;
	}

	static ArrayList<Integer> getSquares(int n) {
		ArrayList<Integer> list = new ArrayList<>();
		int x = 1;
		while (x * x <= n) {
			list.add(x * x);
			x++;
		}
		Collections.reverse(list);
		return list;
	}

}

class Pair {

	int x;
	int y;

	public Pair(int x, int y) {
		this.x = x;
		this.y = y;
	}

	@Override
	public String toString() {
		return "Pair [x=" + x + ", y=" + y + "]";
	}
}

class OutputWriter {
	public PrintWriter writer;

	public OutputWriter(OutputStream outputStream) {
		writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
	}

	public OutputWriter(Writer writer) {
		this.writer = new PrintWriter(writer);
	}

	public void print(Object... objects) {
		for (int i = 0; i < objects.length; i++) {
			if (i != 0)
				writer.print(' ');
			writer.print(objects[i]);
		}
	}

	public void println(Object... objects) {
		print(objects);
		writer.println();
	}

	public void close() {
		writer.close();
	}
}

class InputReader {
	private BufferedReader reader;
	private StringTokenizer tokenizer;

	public InputReader(InputStream stream) {
		reader = new BufferedReader(new InputStreamReader(stream), 32768);
		tokenizer = null;
	}

	public String next() {
		while (tokenizer == null || !tokenizer.hasMoreTokens()) {
			try {
				tokenizer = new StringTokenizer(reader.readLine());
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		return tokenizer.nextToken();
	}

	public String readLine() {
		try {
			return reader.readLine();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	public char nextChar() {
		return next().charAt(0);
	}

	public int nextInt() {
		return Integer.parseInt(next());
	}

	public long nextLong() {
		return Long.parseLong(next());
	}

	public double nextDouble() {
		return Double.parseDouble(next());
	}

	public float nextFloat() {
		return Float.parseFloat(next());
	}

}