#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline bool uax(T &x, T y) {
  return (y > x) ? x = y, true : false;
}
template <typename T>
inline bool uin(T &x, T y) {
  return (y < x) ? x = y, true : false;
}
void err(istream_iterator<string>) {}
template <typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
  cerr << *it << " =: " << a << endl;
  err(++it, args...);
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, pair<T1, T2> &buf) {
  return os << "(" << buf.first << ": " << buf.second << ")";
}
template <typename T>
ostream &operator<<(ostream &os, vector<vector<T>> &A) {
  for (auto &B : A) os << '\n' << B;
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, vector<T> &A) {
  bool f = false;
  os << "{";
  for (auto &e : A) {
    if (f) os << ", ";
    os << e;
    f = true;
  }
  return os << "}";
}
template <typename T>
ostream &operator<<(ostream &os, set<T> &A) {
  bool f = false;
  os << "{";
  for (auto &e : A) {
    if (f) os << ", ";
    os << e;
    f = true;
  }
  return os << "}";
}
template <typename T>
ostream &operator<<(ostream &os, multiset<T> &A) {
  bool f = false;
  os << "{";
  for (auto &e : A) {
    if (f) os << ", ";
    os << e;
    f = true;
  }
  return os << "}";
}
template <typename K, typename V>
ostream &operator<<(ostream &os, map<K, V> &A) {
  bool f = false;
  os << "{";
  for (auto &e : A) {
    if (f) os << ", ";
    os << e;
    f = true;
  }
  return os << "}";
}
template <typename T>
void kek(T ans) {
  cout << ans << endl;
  exit(0);
}
int const MOD = 1000000007;
long long const INF = 1e18;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  string s;
  cin >> s;
  long long int ans = 0;
  int n = int((s).size());
  int lf = -1;
  for (int r = 2; r < n; ++r) {
    for (int k = 1; k < 1000; ++k) {
      if (r - k - k <= lf) break;
      if (s[r] == s[r - k] && s[r - k] == s[r - k - k]) {
        lf = r - k - k;
        break;
      }
    }
    ans += lf + 1;
  }
  kek(ans);
  return 0;
}
