package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var rdr = bufio.NewReaderSize(os.Stdin, 1000000)

func main() {
	sc.Split(bufio.ScanWords)
	s := nextLine()
	l := len(s) - 1
	pl := 0

	check := func(s string) bool {
		half := len(s) / 2
		for k := 0; k < half; k++ {
			if s[k] != s[len(s)-1-k] {
				return false
			}
		}
		return true
	}

	for i := 0; i < l; i++ {
		for j := l; j > i; j-- {
			subs := s[i:j]
			if check(subs) && len(subs) > pl {
				pl = len(subs)
			}
		}
	}

	for i := 1; i < l; i++ {
		subs := s[i:len(s)]
		if check(subs) && len(subs) > pl {
			pl = len(subs)
		}
	}
	fmt.Println(pl)
}

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	i, _ := strconv.Atoi(nextLine())
	return i
}

func nextInt64() int64 {
	i, _ := strconv.ParseInt(nextLine(), 10, 64)
	return i
}

func nextUint64() uint64 {
	i, _ := strconv.ParseUint(nextLine(), 10, 64)
	return i
}

func nextFloat() float64 {
	f, _ := strconv.ParseFloat(nextLine(), 64)
	return f
}

func readLine() string {
	buf := make([]byte, 0, 1000000)
	for {
		l, p, e := rdr.ReadLine()
		if e != nil {
			panic(e)
		}
		buf = append(buf, l...)
		if !p {
			break
		}
	}
	return string(buf)
}

func factor(n uint64) []uint64 {
	if n <= 1 {
		return []uint64{n}
	}

	ps := make([]uint64, 0, 100)

	for i := uint64(2); i*i <= n; i++ {
		for n%i == 0 {
			n /= i
			ps = append(ps, i)
		}
	}
	if n > 1 {
		ps = append(ps, n)
	}
	return ps
}

func gcd(a, b uint64) uint64 {
	for ; b != 0; b, a = a%b, b {
	}
	return a
}

func lcm(a, b uint64) uint64 {
	return (a * b) / gcd(a, b)
}