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#include <bits/stdc++.h>
using namespace std;
using LL = long long;
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
#define ssize(x) int(x.size())
template<class A, class B> auto& operator<<(ostream &o, pair<A, B> p) {
    return o << '(' << p.first << ", " << p.second << ')';
}
template<class T> auto operator<<(ostream &o, T x) -> decltype(x.end(), o) {
    o << '{'; int i = 0; for(auto e : x) o << (", ")+2*!i++ << e; return o << '}';
}
ostream& operator<<(ostream &o, string &s) {
    return o << s.data();   
}
#ifdef DEBUG
#define debug(x...) cerr << "[" #x "]: ", [](auto... $) {((cerr << $ << "; "), ...); }(x), cerr << '\n'
#else
#define debug(...) {}
#endif

int main() {
    cin.tie(0)->sync_with_stdio(0);

    string s;
    cin >> s;
    int n = ssize(s);
    LL ans = 0;

    // 3
    map<pair<int, int>, int> cnt;
    cnt[{0, 0}] = 1;
    int a = 0, b = 0;
    REP(i, n) {
        if (s[i] == 'a')
            a++;
        else if (s[i] == 'c')
            b--;
        else {
            a--;
            b++;
        }
        ans += (LL) (cnt[{a, b}]);
        cnt[{a, b}]++;
    }

    // 2
    auto count_pair = [&](char c1, char c2) {
        map<int, int> hm;
        hm[0] = 1;
        int dif = 0;
        REP(i, n) {
            if (s[i] != c1 && s[i] != c2) {
                dif = 0;
                hm.clear();
                hm[0] = 1;
                continue;
            }
            if (s[i] == c1)
                dif++;
            else
                dif--;
            ans += (LL) (hm[dif]);
            hm[dif]++;
        }
    };
    count_pair('a', 'b');
    count_pair('a', 'c');
    count_pair('b', 'c');

    // 1
    auto count = [&](char c) {
        int sum = 0;
        REP(i, n) {
            if (s[i] != c)
                sum = 0;
            else {
                sum++;
                ans += (LL) (sum);
            }
        }
    };
    count('a');
    count('b');
    count('c');

    cout << ans << '\n';

    return 0;
}