#include <bits/stdc++.h>
using namespace std;
string str;
long long solve() {
  long long ans = 0;
  long long prev_ans = 0;
  for (long long i = 0; i < str.length(); i++) {
    long long k = 1;
    long long ans1 = -1;
    while ((i - 2 * k) >= 0 &&
           !(str[i] == str[i - k] && str[i] == str[i - 2 * k])) {
      k++;
    }
    if ((i - (2 * k)) >= 0)
      ans1 = k;
    else {
      ans = ans + prev_ans;
      continue;
    }
    ans1 = k;
    long long ans2 = max(prev_ans, max((long long)0, i - (2 * k) + 1));
    prev_ans = max(prev_ans, ans2);
    ans = ans + ans2;
  }
  return ans;
}
signed main() {
  cin >> str;
  cout << solve() << "\n";
  return 0;
}
