#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:512000000")
using namespace std;
using li = long long;
using ld = long double;
void solve(bool);
void precalc();
clock_t start;
int main() {
  start = clock();
  int t = 1;
  cout.sync_with_stdio(0);
  cin.tie(0);
  cout.precision(20);
  cout << fixed;
  precalc();
  while (t--) {
    solve(true);
  }
  cout.flush();
  return 0;
}
template <typename T>
T binpow(T q, T w, T mod) {
  if (!w) return 1 % mod;
  if (w & 1) return q * 1LL * binpow(q, w - 1, mod) % mod;
  return binpow(q * 1LL * q % mod, w / 2, mod);
}
template <typename T>
T gcd(T q, T w) {
  while (w) {
    q %= w;
    swap(q, w);
  }
  return q;
}
template <typename T>
T lcm(T q, T w) {
  return q / gcd(q, w) * w;
}
template <typename T>
void make_unique(vector<T>& vec) {
  sort(vec.begin(), vec.end());
  vec.erase(unique(vec.begin(), vec.end()), vec.end());
}
template <typename T>
void relax_min(T& cur, T val) {
  cur = min(cur, val);
}
template <typename T>
void relax_max(T& cur, T val) {
  cur = max(cur, val);
}
mt19937 rng(
    (unsigned long long)chrono::steady_clock::now().time_since_epoch().count());
void precalc() {}
void solve(__attribute__((unused)) bool read) {
  string s;
  cin >> s;
  li n = (li)s.length();
  li res = n * (n + 1) / 2;
  for (li l = 0; l < n; ++l) {
    bool flag = false;
    for (li r = l; r < n && !flag; ++r) {
      for (li i = r - 2; i >= l; i -= 2) {
        if (s[i] == s[r] && s[i] == s[i + (r - i) / 2]) {
          flag = true;
          break;
        }
      }
      if (flag) {
        break;
      }
      --res;
    }
  }
  cout << res << endl;
}
