#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 300000;
char s[MAX_N];
int minRightTriple[MAX_N];
int main() {
  ios::sync_with_stdio(false);
  cin >> s;
  int n = strlen(s);
  fill(begin(minRightTriple), end(minRightTriple), n);
  for (int i = 0; i < n; ++i) {
    char val = s[i];
    for (int x = 1; i + 2 * x < n; ++x) {
      if (s[i + x] == val && s[i + 2 * x] == val) {
        minRightTriple[i] = i + 2 * x;
        break;
      }
    }
  }
  long long res = 0;
  int currMin = n;
  for (int i = n - 1; i >= 0; --i) {
    currMin = min(currMin, minRightTriple[i]);
    res += n - currMin;
  }
  cout << res << endl;
  return 0;
}
