#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using VD = vector<double>;
using VVD = vector<VD>;
using VS = vector<string>;
using P = pair<ll,ll>;
using VP = vector<P>;
#define rep(i, n) for (ll i = 0; i < ll(n); i++)
#define out(x) cout << x << endl
#define dout(x) cout << fixed << setprecision(10) << x << endl
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define sz(x) (int)(x.size())
#define re0 return 0
#define pcnt __builtin_popcountll
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
constexpr int inf = 1e9;
constexpr ll INF = 1e18;
//using mint = modint1000000007;
using mint = modint998244353;
int di[4] = {1,0,-1,0};
int dj[4] = {0,1,0,-1};

int main(){
    string s;
    cin >> s;
    int n = sz(s);
    ll ans = 0;
    rep(m,26)rep(a,26){
        if(m == a) continue;
        VVL dp(n+1,VL(4));
        dp[0][0] = 1;
        rep(i,n){
            rep(v,4) dp[i+1][v] += dp[i][v];
            if(s[i]-'A' == m){
                dp[i+1][1] += dp[i][0];
                dp[i+1][2] += dp[i][1];
            }
            if(s[i]-'A' == a){
                dp[i+1][3] += dp[i][2];
            }
        }
        ans += dp[n][3];
    }
    out(ans);
}