import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.stdio;
import std.string;
import std.range;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

ulong calc(string s) {
    for (ulong i = s.length - 1; i > 0; i--) { // 回文の長さ
        for (int j = 0; j < s.length; j++) { // 回文の開始位置
            int front = j;
            int back = cast(int)(front + i - 1);
            if (back >= s.length)
                break;

            bool found = true;
            while (front <= back) {
                if (s[front] != s[back]) {
                    found = false;
                    break;
                }
                front++;
                back--;
            }

            if (found) {
                return i;
            }
        }
    }
    return 1;
}

void main() {
    auto s = readln.chomp;
    writeln(calc(s));
}