Problem:
Score : 500 points

Problem Statement

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.

Sample Input 1

010

Sample Output 1

2

We can turn all the characters of S into 0 by the following operations:

Perform the operation on the segment S[1,3] with length 3. S is now 101.

Perform the operation on the segment S[1,2] with length 2. S is now 011.

Perform the operation on the segment S[2,3] with length 2. S is now 000.

Sample Input 2

100000000

Sample Output 2

8

Sample Input 3

00001111

Sample Output 3

4

Solution in Kotlin (1.0.0) (judge verdict: Accepted)

fun min(x: Int, y: Int): Int {
    return if (x < y) x else y
}

fun max(x: Int, y: Int): Int {
    return if (x > y) x else y
}


fun main(args: Array<String>) {
    val s = readLine()!!
    val n = s.length
    var ans = n
    for (i in 0..(n-2)) {
        if (s[i] != s[i + 1]) {
            ans = min(max(i + 1, n - i - 1), ans)
        }
    }
    println(ans)
}