p03480 AtCoder Beginner Contest 083 - Wide Flip
You are given a string S consisting of `0` and `1`. Find the maximum integer K not greater than |S| such that we can turn all the characters of S into `0` by repeating the following operation some number of times.

* Choose a contiguous segment [l,r] in S whose length is at least K (that is, r-l+1\geq K must be satisfied). For each integer i such that l\leq i\leq r, do the following: if S_i is `0`, replace it with `1`; if S_i is `1`, replace it with `0`.

Constraints

* 1\leq |S|\leq 10^5
* S_i(1\leq i\leq N) is either `0` or `1`.

Input

Input is given from Standard Input in the following format:


S


Output

Print the maximum integer K such that we can turn all the characters of S into `0` by repeating the operation some number of times.

Examples

Input

010


Output

2


Input

100000000


Output

8


Input

00001111


Output

4
```python
s = input()



tmp = []
for i in range(len(s)-1):
        if s[i] != s[i+1]:
                tmp.append(max(i+1,len(s)-(i+1)))

if len(tmp) == 0:
        #元から全部同じ
        print(len(s))
else:
        print(min(tmp))
```