#include <bits/stdc++.h>
using namespace std;
const long long inf = 1e17 + 10;
const int N = 4e6 + 10;
const long long mod = 1e9 + 7;
const int base = 131;
const double pi = acos(-1);
map<string, int> ml;
map<int, int> vi;
long long b[N], vis[N], dep[N], num[N], a[N], n, m, k, x, y;
long long ex, ey, cnt, ans, sum, flag, t;
long long nex[N], can[N];
vector<int> res, v;
map<char, int> mp;
string s;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> s;
  x = s.size() - 1;
  int r = x + 1;
  n = x;
  for (int i = x; i >= 0; i--) {
    for (int j = 1; i + 2 * j < r; j++) {
      if (s[i] == s[i + j] && s[i] == s[i + 2 * j]) {
        r = i + 2 * j;
      }
    }
    ans += n - r + 1;
  }
  cout << ans;
}
