#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 5;
const int bignum = 5e5 + 5;
char s[maxn];
int d[maxn], n;
long long ans;
int main() {
  scanf("%s", s);
  n = strlen(s);
  for (int i = 0; i <= n; i++) d[i] = bignum;
  for (int i = 0; i < n; i++) {
    for (int j = 1; j <= 20; j++) {
      if (i + 2 * j >= n) break;
      if (s[i] == s[i + j] && s[i + j] == s[i + 2 * j]) {
        d[i] = i + 2 * j;
        break;
      }
    }
  }
  for (int i = n - 2; i >= 0; i--) {
    d[i] = min(d[i], d[i + 1]);
    if (d[i] != bignum) ans = ans + n - d[i];
  }
  printf("%I64d\n", ans);
  return 0;
}
