#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
const double eps = 1e-8;
const long long mod = 1e9 + 7;
const int inf = 1 << 28;
const int maxn = 600005;
void err() {
  puts("-1");
  exit(0);
}
int n, m;
int a[maxn], b[maxn];
void solve() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string s;
  cin >> s;
  int n = s.size();
  long long ret = 0;
  int la = n;
  for (int l = n - 1; l >= 0; l--) {
    for (int k = 1; l + 2 * k < la; k++) {
      if (s[l] == s[l + k] && s[l] == s[l + 2 * k]) {
        la = l + 2 * k;
        break;
      }
    }
    ret += n - la;
  }
  cout << ret;
}
int main() {
  int tc = 1;
  for (int tt = 0; tt < (int)(tc); ++tt) {
    solve();
  }
}
