#include <bits/stdc++.h>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    freopen("pscpld.in", "r", stdin);
    freopen("pscpld.out", "w", stdout);

    string s;
    cin >> s;
    int n = s.size();

    string t = "@";
    for (char c : s) {
        t += "#";
        t += c;
    }
    t += "#$";

    int m = t.size();
    vector<int> p(m, 0);
    int center = 0, right = 0;
    long long total = 0;

    for (int i = 1; i < m - 1; i++) {
        int mirror = 2 * center - i;
        if (i < right)
            p[i] = min(right - i, p[mirror]);
        while (t[i + (1 + p[i])] == t[i - (1 + p[i])])
            p[i]++;
        if (i + p[i] > right) {
            center = i;
            right = i + p[i];
        }
        total += (p[i] + 1) / 2;
    }

    cout << total << "\n";
    return 0;
}