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 Scala (2.11.7) (judge verdict: Wrong Answer)


object Main extends App {
	val temp = scala.io.StdIn.readLine.toArray.map(_.toInt - 48)

	for(i<-0 until temp.size - 1){
		if(temp(i) < temp(i+1)){
			temp(i) = 1
			temp(i+1) = 0
		}
	}

	var rf = true
	var lf = true
	var r = 0
	var l = 0

	for(i<-temp){
		if(i == 0){
			if(rf) r = r + 1
			else r = 1
		}else{
			if(lf) l = l + 1
			else l = 1
		}
	}

	if(l>r) println(l)
		else println(r)

}