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

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    string s;
    cin >> s;
    int n = (int)s.length();
    int ans = 0;
    vector<vector<char>> f(n, vector<char>(n, 0)); // f[i][j]：反转 s[i..j] 后是否更小
    for (int len = 2; len <= n; len++)
    {
        for (int i = 0; i + len <= n; i++)
        {
            int j = i + len - 1;
            if (s[i] == s[j]) // 两端相同,往里看
                f[i][j] = (len > 2) ? f[i + 1][j - 1] : 0;
            else
                f[i][j] = (s[i] > s[j]); // 大的那个被挪到了前面 → 变小
            ans += f[i][j];
        }
    }
    cout << ans;
    return 0;
}