import scala.collection.immutable.IndexedSeq
import scala.io.StdIn

object Problem273 {

  def calcPalindromeLen(S: IndexedSeq[Char], start: Int, end: Int): Int = {
    val surroundLen = ((0 to S.length) takeWhile { i =>
      val startIndex = start - i
      val endIndex = end + i
      startIndex >= 0 && endIndex < S.length && S(startIndex) == S(endIndex)
    }).last

    (end - start + 1) + surroundLen * 2
  }

  def proc(S: IndexedSeq[Char]): Int = {

    if(S.length == 2){
      return 1
    }

    val evenPalindromesLen = {
      for {
        i <- 0 until S.length - 1
        if S(i) == S(i + 1)
        len = calcPalindromeLen(S, i, i + 1)
      } yield {
        if (len == S.length) len - 2 else len
      }
    }

    val oddPalindromesLen = {
      for {
        i <- 1 until S.length - 1
        if S(i - 1) == S(i + 1)
        len = calcPalindromeLen(S, i - 1, i + 1)
      } yield {
        if (len == S.length) len - 2 else len
      }
    }

    val allPalindromesLen = evenPalindromesLen ++ oddPalindromesLen
    if (allPalindromesLen.isEmpty) 1 else allPalindromesLen.max
  }

  def main(args: Array[String]) {
    val S: IndexedSeq[Char] = StdIn.readLine().toIndexedSeq

    val result = proc(S)
    println(result)
  }

}