#include <bits/stdc++.h>

using namespace std;

const int NMAX(2000005);
int pal[NMAX];
string s, sir2;

int main()
{
    ios_base::sync_with_stdio(false);
    freopen("pscpld.in", "r", stdin);
    freopen("pscpld.out", "w", stdout);
    cin >> s;
    sir2 += '#';
    for(auto it: s)
    {
        sir2 += it;
        sir2 += '#';
    }

    pal[1] = 1;
    int c = 1, dr = 1;
    long long rez = 0;
    for(int i = 1; i < (int)sir2.size(); ++i){
        int lg = 0;
        if(i <= dr)
            lg = min(pal[2 * c - 1], dr - i + 1);
        while(i - lg >= 0 && i + lg < (int)sir2.size() && sir2[i + lg] == sir2[i - lg])
            ++lg;

        if(i + lg - 1 > dr){
            dr = i + lg - 1;
            c = i;
        }

        pal[i] = lg;
        if(i % 2 == 0)
            rez += lg / 2;
        else rez += (lg + 1) / 2;
    }

    cout << rez << '\n';
    return 0;
}