#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
template <class T>
bool ckmin(T& a, const T& b) {
  return a > b ? a = b, 1 : 0;
}
template <class T>
bool ckmax(T& a, const T& b) {
  return a < b ? a = b, 1 : 0;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 3e5 + 10;
vector<int> p[2];
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  string s;
  cin >> s;
  int n = int((s).size());
  ll ans = n;
  ans *= n + 1;
  ans /= 2;
  for (auto l = (0); l < (n); ++l) {
    for (auto r = (l); r < (n); ++r) {
      if ([&]() {
            for (int k = 1; r - 2 * k >= l; ++k)
              if (s[r] == s[r - k] && s[r - k] == s[r - 2 * k]) return 1;
            return 0;
          }())
        break;
      --ans;
    }
  }
  cout << ans;
}
