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.util.*;
import java.io.*;

public class MakeASquare {
    PrintWriter out;
    StringTokenizer st;
    BufferedReader br;
    final int imax = Integer.MAX_VALUE, imin = Integer.MIN_VALUE;
    final int mod = 1000000007;

    void solve() throws Exception {
        int t = 1;
//        t = ni();
        for (int ii = 0; ii < t; ii++) {
            char[] a= ns().toCharArray();
            ans= 0;
            helper(a, 0, new char[10], 0);

            if(ans!= 0) out.println(a.length- ans);
            else out.println(-1);
        }
    }

    int ans;
    private void helper(char[] a, int i, char[] arr, int j) {
        if(i== a.length) {
            StringBuilder num= new StringBuilder();
            for(int k=0;k<arr.length;k++) {
                if(arr[k]== '\u0000') break;
                else num.append(arr[k]);
            }

            if(num.length()== 0 || num.charAt(0)== '0') return;
//            out.println(num);
            int val= Integer.parseInt(num.toString());
            if((int)Math.sqrt(val)*(int)Math.sqrt(val)== val) ans= Math.max(ans, num.length());
        }
        else {
            helper(a, i+1, arr, j);
            arr[j]= a[i];
            helper(a, i+1, arr, j+1);
            arr[j]= '\u0000';
        }
    }

    public static void main(String[] args) throws Exception {
        new MakeASquare().run();
    }

    void run() throws Exception {
        if (System.getProperty("ONLINE_JUDGE") == null) {
            File file = new File("C:\\college\\CodeForces\\inputf.txt");
            br = new BufferedReader(new FileReader(file));
            out = new PrintWriter("C:\\college\\CodeForces\\outputf.txt");
        } else {
            out = new PrintWriter(System.out);
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        long ss = System.currentTimeMillis();
        st = new StringTokenizer("");
        while (true) {
            solve();
            String s = br.readLine();
            if (s == null) break;
            else st = new StringTokenizer(s);
        }
        //out.println(System.currentTimeMillis()-ss+"ms");
        out.flush();
    }

    void read() throws Exception {
        st = new StringTokenizer(br.readLine());
    }

    int ni() throws Exception {
        if (!st.hasMoreTokens()) read();
        return Integer.parseInt(st.nextToken());
    }

    char nc() throws Exception {
        if (!st.hasMoreTokens()) read();
        return st.nextToken().charAt(0);
    }

    String nw() throws Exception {
        if (!st.hasMoreTokens()) read();
        return st.nextToken();
    }

    long nl() throws Exception {
        if (!st.hasMoreTokens()) read();
        return Long.parseLong(st.nextToken());
    }

    int[] ni(int n) throws Exception {
        int[] ret = new int[n];
        for (int i = 0; i < n; i++) ret[i] = ni();
        return ret;
    }

    long[] nl(int n) throws Exception {
        long[] ret = new long[n];
        for (int i = 0; i < n; i++) ret[i] = nl();
        return ret;
    }

    double nd() throws Exception {
        if (!st.hasMoreTokens()) read();
        return Double.parseDouble(st.nextToken());
    }

    String ns() throws Exception {
        String s = br.readLine();
        return s.length() == 0 ? br.readLine() : s;
    }

    void print(int[] arr) {
        for (int i : arr) out.print(i + " ");
        out.println();
    }

    void print(long[] arr) {
        for (long i : arr) out.print(i + " ");
        out.println();
    }

    void print(int[][] arr) {
        for (int[] i : arr) {
            for (int j : i) out.print(j + " ");
            out.println();
        }
    }

    void print(long[][] arr) {
        for (long[] i : arr) {
            for (long j : i) out.print(j + " ");
            out.println();
        }
    }

    long add(long a, long b) {
        if (a + b >= mod) return (a + b) - mod;
        else return a + b >= 0 ? a + b : a + b + mod;
    }

    long mul(long a, long b) {
        return (a * b) % mod;
    }

    void print(boolean b) {
        if (b) out.println("YES");
        else out.println("NO");
    }

    long binExp(long base, long power) {
        long res = 1l;
        while (power != 0) {
            if ((power & 1) == 1) res = mul(res, base);
            base = mul(base, base);
            power >>= 1;
        }
        return res;
    }

    long gcd(long a, long b) {
        if (b == 0) return a;
        else return gcd(b, a % b);
    }

    // strictly smaller on left
    void stack_l(int[] arr, int[] left) {
        Stack<Integer> stack = new Stack<>();
        for (int i = 0; i < arr.length; i++) {
            while (!stack.isEmpty() && arr[stack.peek()] >= arr[i]) stack.pop();
            if (stack.isEmpty()) left[i] = -1;
            else left[i] = stack.peek();
            stack.push(i);
        }
    }

    // strictly smaller on right
    void stack_r(int[] arr, int[] right) {
        Stack<Integer> stack = new Stack<>();
        for (int i = arr.length - 1; i >= 0; i--) {
            while (!stack.isEmpty() && arr[stack.peek()] >= arr[i]) stack.pop();
            if (stack.isEmpty()) right[i] = arr.length;
            else right[i] = stack.peek();
            stack.push(i);
        }
    }

    private void sort(int[] arr) {
        List<Integer> list = new ArrayList<>();
        for (int i : arr) list.add(i);
        Collections.sort(list);
        for (int i = 0; i < arr.length; i++) arr[i] = list.get(i);
    }
}