const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;
void async function () {
// Write your code here
while(line = await readline()){
let max=0
for(let i=0;i<line.length;i++){
for(let j=i+1;j<=line.length;j++){
let substr=line.slice(i,j)
let str=substr.slice(0,substr.length/2).split('').reverse().join('')
max=substr.slice(-(substr.length/2)).includes(str)?Math.max(max,substr.length):max
}
}
console.log(max);
}
}()