#include <iostream>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;

int main() {
  string s;
  cin >> s;

  int ans = 0;
  for (int i = 0; i < s.size(); i++) {
    for (int j = 0; j < i; j++) {
      if (s[j] > s[i]) ans++;
    }
  }
  cout << ans << endl;
}