#include <bits/stdc++.h>
using namespace std;
const int maxnodes = 1005;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  string s;
  cin >> s;
  n = s.length();
  vector<int> ml(n, -1);
  set<int> st;
  for (int i = 0; i < n; i++) {
    st.insert(i);
  }
  for (int k = 1; k < n; k++) {
    vector<int> er;
    for (auto it : st) {
      if (it + 2 * k > n) break;
      if (s[it] == s[it + k] and s[it] == s[it + 2 * k]) {
        ml[it + 2 * k] = max(ml[it + 2 * k], it);
        er.push_back(it);
      }
    }
    for (auto it : er) st.erase(it);
  }
  long long ans = 0;
  int r = -1;
  for (int i = 0; i < n; i++) {
    r = max(r, ml[i]);
    ans += (r + 1);
  }
  cout << ans;
  return 0;
}
