#include <bits/stdc++.h>
#define int long long

using namespace std;

ifstream fin ("pscpld.in");
ofstream fout ("pscpld.out");

int mnch[2000002];

signed main()
{

    string S, citit;
    fin >> citit;
    S = "&&";
    for (auto x:citit){
        S += x;
        S += "&";
    }
    int best = 0;
    for (int i=1;i<S.size();++i){
        if (best+mnch[best]>=i){
            mnch[i] = min(mnch[best-(i-best)],best+mnch[best]-i);
            while (i+mnch[i]+1<S.size() and i-mnch[i]-1>=1 and S[i+mnch[i]+1]==S[i-mnch[i]-1]){
                mnch[i]++;
            }
            if (i+mnch[i]>=best+mnch[best]){
                best = i;
            }
        }else{
            mnch[i] = 0;
            while (i+mnch[i]+1<S.size() and i-mnch[i]-1>=1 and S[i+mnch[i]+1]==S[i-mnch[i]-1]){
                mnch[i]++;
            }
            best = i;
        }
    }
    int ans = 0;
    for (int i=1;i<S.size();++i){
        ans +=(mnch[i]+1)/2;
    }
    fout << ans;
    return 0;
}