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 PYTHON3):

Solution:
s=input()
if s[-1]=='1':
  print(-1)
  exit()
if s[-2]=='0':
  print(-1)
  exit()

t=s[:-1]
D=[]
for i in range((len(t)+1)//2):
  if t[i]!=t[-1-i]:
    print(-1)
    exit()
m=1
A=[]
for i in range(1,len(s)//2+1):
    A.append((m,i+1))
    if s[i-1]=='1':
        m=i+1
for i in range(len(s)//2+2,len(s)+1):
    A.append((m,i))
for i in A:
    print(*i)