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

int main(){
    string S;
    cin >> S;
    int l = S.length();
    vector<int> dp(l+1,0);
    map<char,int> ser;
    ser[S[0]]++;
    ser[S[1]]++;
    if(S[0] == S[1] && S[2] != S[1]){
        dp[3] = 1;
    }
    ll next = 0;
    for(int i=4;i<=l;i++){
        int x = ser[S[i-2]];
        if(x != 0){
            if(S[i-1] == S[i-2]){
                dp[i] += x;
            }else{
                dp[i]+=x+next;
                next = 0;
            }
        }
        ser[S[i-2]]++;
        int y = ser[S[i-1]];
        if(y >= 2){
            ll down = y*(y-1)/2;
            dp[i]+=dp[i-1]-down;
            next = down;
        }else{
            dp[i] += dp[i-1];
        }
    }
    for(int i=1;i<=l;i++){
        dp[i] += dp[i-1];
    }
    cout << dp[l] << endl;
}