#include <iostream>

using namespace std;

int main(void) {
  string s;
  cin >> s;
  int n = s.size();
  long long dp[n+1][26][3];
  for (int i = 0; i < n+1; i++) {
    for (int j = 0; j < 26; j++) {
      for (int k = 0; k < 3; k++) {
        dp[i][j][k] = 0;
      }
    }
  }
  for (int i = 0; i < n; i++) {
    int c = s[i] - 'A';
    for (int j = 0; j < 26; j++) {
      for (int k = 0; k < 3; k++) {
        dp[i+1][j][k] += dp[i][j][k];
      }
      if (c != j) {
        dp[i+1][c][2] += dp[i][j][1];
      }
    }
    dp[i+1][c][0] += 1;
    dp[i+1][c][1] += dp[i][c][0];
  }
  long long ans = 0;
  for (int i = 0; i < 26; i++) {
    ans += dp[n][i][2];
  }
  cout << ans << endl;
}