#include <bits/stdc++.h>

#define NMAX 2000005
using namespace std;

string s, s2;
int v[2 * NMAX];

int main()
{
    ios_base::sync_with_stdio(false);
    freopen("pscpld.in", "r", stdin);
    freopen("pscpld.out", "w", stdout);

    cin >> s;

    s2 += '#';
    for(auto it: s){
        s2 += it;
        s2 += '#';
    }

    v[0] = 1;
    int c = 0, r = 0;
    long long rez = 0;
    for(int i = 1; i < s2.size(); ++i){
        int lg = 0;
        if(i <= r)
            lg = min(v[2 * c - i], r - i + 1);
        while(i - lg >= 0 && i + lg < s2.size() && s2[i - lg] == s2[i + lg])
            ++lg;

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

        v[i] = lg;

        if(i % 2 == 0)
            rez += lg / 2;
        else rez += (lg + 1) / 2;
    }
    cout << rez << '\n';
    return 0;
}