// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops", "omit-frame-pointer", "inline")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx,avx2,fma,tune=native")
// #pragma GCC option("arch=native", "no-zero-upper") // Enable AVX

/// UH Top
#include <bits/stdc++.h>
#define db(x) cerr << #x << ':' << (x) << '\n';
#define all(v) (v).begin(), (v).end()
#define allr(v) (v).rbegin(), (v).rend()
// #define int ll
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
// typedef __int128_t int128;
typedef pair<ll, ll> pii;
typedef pair<ld, ll> pdi;
typedef pair<ld, ld> pdd;
typedef pair<ld, pdd> pdp;
typedef pair<string, ll> psi;
typedef pair<ll, string> pls;
typedef pair<string, string> pss;
typedef pair<ll, pii> pip;
typedef pair<pii, pii> ppp;
typedef complex<ld> point;
typedef vector<point> polygon;
typedef vector<ll> vi;
typedef pair<point, int> ppi;
#define prec(n)        \
    cout.precision(n); \
    cout << fixed
const ll mod = (1e9 + 7);
const ld eps = (1e-9);
const ll oo = (ll)(1e18 + 5);
#define pi acos(-1)
#define MAXN (ll)(1e6 + 5)

string s;

vector<int> manacher(const string &s)
{
	int n = 2 * s.length();
	vector<int> rad(n);

	for (int i = 0, j = 0, k; i < n; i += k, j = max(j - k, 0))
	{
		for (; i >= j && i + j + 1 < n
			&& s[(i - j) / 2] == s[(i + j + 1) / 2]; ++j);
		rad[i] = j;
		for (k = 1; i >= k &&
			rad[i] >= k && rad[i - k] != rad[i] - k; ++k)
			rad[i + k] = min(rad[i - k], rad[i] - k);
	}

	return rad;
}

bool is_pal(const vector<int> &rad, int b, int e)
{
	int n = rad.size() / 2;
	return b >= 0 && e < n && rad[b + e] >= e - b + 1;
}


int solve(int l,int r,vector<int>& x)
{
    int sz=r-l+1;
    for(int i=1;i<=sz/2;i++)
    {
        if(is_pal(x,l,l+2*i-1))
            return solve(l+i,r,x);
        if(is_pal(x,r-2*i+1,r))
            return solve(l,r-i,x);
    }
    return sz;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> s;
    
    auto x=manacher(s);

    cout << solve(0,s.size()-1,x) << '\n';

    return 0;
}