#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
const long long INF = 1e9 + 10;
const long long BINF = 1e18 + 10;
void source() {
  string s;
  cin >> s;
  long long cur = -1, ans = 0;
  for (long long i = 2; i < (long long)s.size(); i++) {
    long long pos = -1;
    for (long long len = 1; i - 2 * len >= 0; len++) {
      if (s[i] == s[i - len] && s[i - len] == s[i - 2 * len]) {
        pos = i - 2 * len;
        break;
      }
    }
    cur = max(cur, pos);
    ans += cur + 1;
  }
  cout << ans;
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  source();
  return 0;
}
