let str;
while(str = readline()) {
function getStringLength(key) {
key = key.split('');
let len = key.length;
let max = 0;
for(let i = 0;i<len;i++) {
let low = i;
let high = i+1;
while(key[low] == key[high]&&low>=0&&high<=len-1) {
low--;
high++;
}
max = Math.max(max,high-low-1);
let lower = i;
let higher = i+2;
while(key[lower] == key[higher]&&lower>=0&&higher<=len-1) {
lower--;
higher++;
}
max = Math.max(max,higher-lower-1);
}
console.log(max);
};
getStringLength(str);
}
while(str = readline()) {
function getStringLength(key) {
key = key.split('');
let len = key.length;
let max = 0;
for(let i = 0;i<len;i++) {
let low = i;
let high = i+1;
while(key[low] == key[high]&&low>=0&&high<=len-1) {
low--;
high++;
}
max = Math.max(max,high-low-1);
let lower = i;
let higher = i+2;
while(key[lower] == key[higher]&&lower>=0&&higher<=len-1) {
lower--;
higher++;
}
max = Math.max(max,higher-lower-1);
}
console.log(max);
};
getStringLength(str);
}