#include <bits/stdc++.h>
#pragma GCC optimize("O2")
using namespace std;
const int N = 1e6 + 10;
const long long mod = 1e9 + 7;
const long long mod2 = 998244353;
const long long inf = 8e18;
const int LOG = 22;
long long pw(long long a, long long b, long long M) {
  return (!b ? 1
             : (b & 1 ? (a * pw(a * a % M, b / 2, M)) % M
                      : pw(a * a % M, b / 2, M)));
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  string s;
  cin >> s;
  int n = (int)s.size();
  long long ans = 0;
  for (int l = 0; l < n; l++) {
    ans += max(0, n - l - 10);
    if (l + 2 > n) continue;
    for (int r = l + 2; r < min(l + 10, n); r++) {
      bool is_OK = 0;
      for (int x1 = l; x1 <= r; x1++) {
        for (int x2 = x1 + 1; x2 <= r; x2++) {
          if (s[x1] == s[x2] && 2 * x2 - x1 <= r && s[2 * x2 - x1] == s[x1]) {
            is_OK = 1;
          }
        }
      }
      ans += is_OK;
    }
  }
  cout << ans;
  return 0;
}
