#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 10;
char s[maxn];
int main() {
  scanf("%s", s + 1);
  int len = strlen(s + 1);
  long long ans = 0;
  int r = len + 1;
  for (int i = len; i >= 1; i--) {
    r = min(r, i + 9);
    for (int j = 1; i + 2 * j <= len; j++) {
      if (s[i] == s[i + j] && s[i] == s[i + 2 * j]) {
        r = min(r, i + 2 * j);
        break;
      }
    }
    ans += len - r + 1;
  }
  printf("%I64d\n", ans);
  return 0;
}
