#include <bits/stdc++.h>
using namespace std;
vector<char> V;
const long long MOD = 998244353;
long long ans[1000000];
int a[10000000];
long long poww(long long a, long long n, long long m) {
  long long ans = 1;
  while (n) {
    if (n & 1) {
      ans = (ans * a) % m;
    }
    a = (a * a) % m;
    n >>= 1;
  }
  return ans;
}
int n, m;
int tp[100];
bool judge(int x) {
  int gg = a[1];
  if (a[1] + x >= m) {
    gg = 0;
  }
  for (int i = 2; i <= n; i++) {
    if (a[i] > gg) {
      if (a[i] + x >= m && (a[i] + x) - m >= gg) {
      } else {
        gg = a[i];
      }
    } else {
      if (a[i] + x >= gg) {
      } else {
        return false;
      }
    }
  }
  return true;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  string s;
  cin >> s;
  int len = s.length();
  int last = len;
  long long sum = 0;
  for (int i = len - 1; i >= 0; i--) {
    int cnt = 0;
    for (int j = i + 1; j < len; j++) {
      cnt++;
      if (j + cnt >= len) break;
      if (s[j] == s[i] && s[j] == s[j + cnt]) {
        if (j + cnt <= last) {
          last = j + cnt;
        }
        break;
      }
    }
    sum += (len - (last));
  }
  cout << sum << "\n";
  return 0;
}
