Problem: You are given a string s of length n. Does a tree with n vertices that satisfies the following conditions exist?

* The vertices are numbered 1,2,..., n.
* The edges are numbered 1,2,..., n-1, and Edge i connects Vertex u_i and v_i.
* If the i-th character in s is `1`, we can have a connected component of size i by removing one edge from the tree.
* If the i-th character in s is `0`, we cannot have a connected component of size i by removing any one edge from the tree.



If such a tree exists, construct one such tree.

Constraints

* 2 \leq n \leq 10^5
* s is a string of length n consisting of `0` and `1`.

Input

Input is given from Standard Input in the following format:


s


Output

If a tree with n vertices that satisfies the conditions does not exist, print `-1`.

If a tree with n vertices that satisfies the conditions exist, print n-1 lines. The i-th line should contain u_i and v_i with a space in between. If there are multiple trees that satisfy the conditions, any such tree will be accepted.

Examples

Input

1111


Output

-1


Input

1110


Output

1 2
2 3
3 4


Input

1010


Output

1 2
1 3
1 4

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

class Main {

    // Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
    public static void main(String[] args) throws Exception {
        final Scanner sc = new Scanner(System.in);
        String s;
        s = sc.next();
        solve(s);
    }

    static void solve(String s){
        String[] str = s.split("");
        int n = str.length;
        int k[] = new int[(int)n+1];
        for(int i = 1 ; i <= n ; i++) k[i] = Integer.parseInt(str[i-1]);
        if( k[1] == 0 || k[n] == 1) exit();
        for(int i = 1 ; i < (n+1)/2 ; i++){
            if(k[i] != k[n-i]) exit();
        }
        int v[] = new int[(int)n];
        int next_one = 1;
        for(int i = 1 ; i < n ; i++){
            if(k[i] == 1){
                for(int j = i+1 ; j < n ; j++){
                    if(k[j] == 1){
                        v[i] = j;
                        next_one = j;
                        break;
                    }
                }
            }else{
                v[i] = next_one;
            }
            v[n-1] = n;
            System.out.println(i + " " + v[i]);
        }
    }

    static void exit(){
        System.out.println(-1);
        System.exit(0);
    }
}