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#include <bits/stdc++.h>
using namespace std;
using LL = long long;
#define e1 first
#define e2 second
#define pb push_back
#define OUT(x) {cout << x << "\n"; exit(0); }
#define TCOUT(x) {cout << x << "\n"; return; }
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define rep(i, l, r) for(int i = (l); i < (r); ++i)
#define boost {ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); }
#define sz(x) int(x.size())
#define trav(a, x) for(auto& a : x)
#define all(x) begin(x), end(x)
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
/*#include <atcoder/modint>
using namespace atcoder;
using mint = modint998244353;
vector <mint> fac, inv;
mint binom(int n, int k) {
	if (n < k || n < 0) return 0;
	return fac[n] * inv[k] * inv[n-k];
}

void prep(int N) {
	fac.resize(N+1, 1); inv.resize(N+1, 1);
	for (int i=1; i<=N; ++i) fac[i] = fac[i-1] * i;
	inv[N] = fac[N].inv();
	for (int i=N-1; i>0; --i) inv[i] = inv[i+1] * (i + 1);
}*/

mt19937_64 rng(time(0));
int random(int l, int r) {
	return uniform_int_distribution<int>(l, r)(rng);
}
#ifdef DEBUG
template<class T> int size(T &&x) {
	return int(x.size());
}
template<class A, class B> ostream& operator<<(ostream &out, const pair<A, B> &p) {
	return out << '(' << p.first << ", " << p.second << ')';
}
template<class T> auto operator<<(ostream &out, T &&x) -> decltype(x.begin(), out) {
	out << '{';
	for(auto it = x.begin(); it != x.end(); ++it)
		out << *it << (it == prev(x.end()) ? "" : ", ");
	return out << '}';
}
void dump() {}
template<class T, class... Args> void dump(T &&x, Args... args) {
	cerr << x << ";  ";
	dump(args...);
}
#endif
#ifdef DEBUG
  struct Nl{~Nl(){cerr << '\n';}};
# define debug(x...) cerr << (strcmp(#x, "") ? #x ":  " : ""), dump(x), Nl(), cerr << ""
#else
# define debug(...) 0 && cerr
#endif
const int maxn = 1000100;

//Did you REAALLY consider sample tests?
ll brut(string &s) {
	int n = sz(s);
	ll ret = 0;
	auto ok = [&](vi v) {
		vi tmp;
		trav(elem, v) {
			if (elem) tmp.pb(elem);
		}
		sort(all(tmp));
		return tmp[0] == tmp.back();
	};
	
	rep(i, 0, n) {
		vi ile(3, 0);
		rep(j, i, n) {
			ile[s[j]-'a']++;
			ret += ok(ile);
		}
	}
	return ret;
}
int sgn(int x) {return x > 0 ? 1 : -1; }

ll wzo(string &s) {
	int n = sz(s);
	vi tmp(n + 1, -1);
	rep(i, 0, n) tmp[i + 1] = s[i] - 'a';
	vi ost(3, 0);
	vi ile(3, 0);
	map<pii, int> M_triple;
	vector <map<int, int> > map_without(3);
	
	vector <vector<pair<pii, int> > > queries_all(n + 1);
	vector <vector<pair<int, int> > > queries_without(n + 1);
	ll res = 0;
	
	auto get_without = [&](vi ile, int without_which) -> int {
		int pytaj;
		if (without_which == 0) pytaj = {ile[2] - ile[1]};
		if (without_which == 1) pytaj = {ile[2] - ile[0]};
		if (without_which == 2) pytaj = {ile[1] - ile[0]};
		return pytaj;
	};
	
	auto get_triple = [&](vi ile) -> pii {
		return make_pair(ile[1] - ile[0], ile[2] - ile[0]);
	};
	
	FOR(i, 1, n) {
		ile[tmp[i]]++;
		ost[tmp[i]] = i;
		
		vector <pii> help(3);
		rep(typ, 0, 3) help[typ] = {ost[typ], typ};
		sort(all(help));
		
		assert(help[2].first == i);
		assert(help[2].second == tmp[i]);
		
		int only_last = help[2].first - help[1].first;
		res += only_last;
		
		auto query_two = [&](int a, int b, int without_which) {
			if (a > b) return;
			int pytaj = get_without(ile, without_which);
			queries_without[b - 1].push_back({pytaj, 1 + without_which});
			if (a > 1) queries_without[a - 2].push_back({pytaj, - (1 + without_which)}); 
		};
		
		auto query_all = [&](int a, int b) {
			if (a > b) return;
			pii pytaj = get_triple(ile);
			queries_all[b - 1].push_back({pytaj, 1});
			if (a > 1) queries_all[a - 2].push_back({pytaj, -1});
		};
		
		query_two(help[0].first + 1, help[1].first, help[0].second);
		query_all(1, help[0].first);
	}
	
	rep(i, 0, 3) ile[i] = 0;
	FOR(i, 0, n) {
		if (i > 0) ile[tmp[i]]++;
		// update relevant maps
		M_triple[get_triple(ile)]++; 
		rep(j, 0, 3) {
			int que = get_without(ile, j);
			map_without[j][que]++;
		}
		
		// query relevant maps
		for (auto [pytaj, typ] : queries_all[i]) {
			res += typ * M_triple[pytaj];
		}
		for (auto [pytaj, without_which] : queries_without[i]) {
			res += sgn(without_which) * map_without[abs(without_which) - 1][pytaj];
		}
	}
	
	return res;
}

bool TEST = 0;

int main() {
	boost;
	string s;
	if (!TEST) {
		cin >> s;
		cout << wzo(s) << "\n";
	}
	else {
		int testcount;
		cin >> testcount;
		FOR(_z, 1, testcount) {
			if (_z % 100 == 0) cout << "OK: " << _z << "\n";
			int n = random(20, 40);
			s = "";
			rep(i, 0, n) s += (char)('a' + random(0, 2));
			auto model = wzo(s);
			auto slow = brut(s);
			if (model != slow) {
				debug(s);
				debug(model);
				debug(slow);
				OUT("WA");
			}
		}
	}
}