#include <bits/stdc++.h>
using namespace std;
const long long MAXN = 1e6 + 10;
const long long INF = 1e9 + 10;
const int MOD = 998244353;
int n, a[MAXN];
string second;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> second;
  n = (int)second.size();
  for (int i = 0; i < n; i++) {
    a[i] = n;
    for (int j = 1; i + 2 * j < min(n, i + 10); j++) {
      if (second[i] == second[i + j] && second[i] == second[i + 2 * j]) {
        a[i] = i + 2 * j;
        break;
      }
    }
  }
  long long ans = (long long)(n + 1) * n / 2;
  int minn = n;
  for (int i = n - 1; i >= 0; i--) {
    minn = min(minn, a[i]);
    ans -= (minn - i);
  }
  cout << ans;
  return 0;
}
