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.

-----Sample Input-----
1111

-----Sample Output-----
-1

It is impossible to have a connected component of size n after removing one edge from a tree with n vertices.

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

ns = {"__name__": "__main__"}
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 'import sys,collections as cl,bisect as bs\nsys.setrecursionlimit(100000)\ninput = sys.stdin.readline\nmod = 10**9+7\nMax = sys.maxsize\ndef l(): #intのlist\n\treturn list(map(int,input().split()))\ndef m(): #複数文字\n\treturn map(int,input().split())\ndef onem(): #Nとかの取得\n\treturn int(input())\ndef s(x): #圧縮\n\ta = []\n\tif len(x) == 0:\n\t\treturn []\n\taa = x[0]\n\tsu = 1\n\tfor i in range(len(x)-1):\n\t\tif aa != x[i+1]:\n\t\t\ta.append([aa,su])\n\t\t\taa = x[i+1]\n\t\t\tsu = 1\n\t\telse:\n\t\t\tsu += 1\n\ta.append([aa,su])\n\treturn a\ndef jo(x): #listをスペースごとに分ける\n\treturn " ".join(map(str,x))\ndef max2(x): #他のときもどうように作成可能\n\treturn max(map(max,x))\ndef In(x,a): #aがリスト(sorted)\n    k = bs.bisect_left(a,x)\n    if k != len(a) and a[k] ==  x:\n        return True\n    else:\n        return False\n\ndef pow_k(x, n):\n    ans = 1\n    while n:\n        if n % 2:\n            ans *= x\n        x *= x\n        n >>= 1\n    return ans\n\n"""\ndef nibu(x,n,r):\n\tll = 0\n\trr = r\n\twhile True:\n\t\tmid = (ll+rr)//2\n\n\tif rr == mid:\n\t\treturn ll\n\tif (ここに評価入れる):\n\t\trr = mid\n\telse:\n\t\tll = mid+1\n"""\n\ns = input()[:-1]\n\nif s[0] == "1" and s[-1] == "0":\n\tk = (len(s)-2)//2\n\n\tfor i in range(k):\n\t\tif s[i] != s[-(2 + i)]:\n\t\t\tprint(-1)\n\t\t\treturn\n\telse:\n\t\t\n\t\tla = len(s)\n\n\t\tfor i in range(la-2,-1,-1):\n\t\t\tif s[i] == "1":\n\t\t\t\tprint(i+1,la)\n\t\t\t\tla = i+1\n\t\t\telse:\n\t\t\t\tprint(i+1,la)\nelse:\n\tprint(-1)'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: