#include <bits/stdc++.h>
using namespace std;
int n;
char s[300010];
int nx[300010], a[300010];
int main() {
  while (scanf("%s", s + 1) != EOF) {
    n = strlen(s + 1);
    int nxx[2] = {n + 1, n + 1};
    for (int i = n; i >= 1; --i) {
      nx[i] = nxx[s[i] - '0'];
      nxx[s[i] - '0'] = i;
    }
    memset(a, 0, sizeof a);
    long long res = 0;
    for (int i = 1; i <= n; ++i) {
      int it = nx[i];
      while (it <= n) {
        int nnx = it + it - i;
        if (nnx > n) {
          break;
        }
        if (s[nnx] == s[i]) {
          a[i] = (n - nnx + 1);
          break;
        }
        it = nx[it];
      }
    }
    for (int i = n; i >= 1; --i) {
      a[i] = max(a[i], a[i + 1]);
      res += a[i];
    }
    printf("%lld\n", res);
  }
  return 0;
}
