#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.size();
  int l[n];
  for (int i = 0; i < n; ++i) {
    l[i] = n;
  }
  for (int i = 0; i < n; ++i) {
    for (int j = 1; j <= min(n - i - 1, i); ++j) {
      if (s[i - j] == s[i] && s[i] == s[i + j]) {
        l[i - j] = min(l[i - j], i + j);
        break;
      }
    }
  }
  set<pair<int, int> > h;
  for (int i = 0; i < n; ++i) {
    h.insert({l[i], i});
  }
  long long sum = 0;
  for (int i = 0; i < n; ++i) {
    sum += n - ((*h.begin()).first);
    h.erase({l[i], i});
  }
  cout << sum;
  return 0;
}
