/* -*- coding: utf-8 -*-
 *
 * 3015.cc:  No.3015 蜿ｳ縺ｫ蟇・○繧・ - yukicoder
 */

#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

using ll = long long;

/* global variables */

char s[MAX_N + 4];

/* subroutines */

/* main */

int main() {
  scanf("%s", s);
  int n = strlen(s);

  ll sum = 0;
  for (int i = 0, x = 0; i < n;) {
    int l1 = 0, l0 = 0;
    while (i < n && s[i] == '1') i++, l1++;
    while (i < n && s[i] == '0') i++, l0++;

    if (l0 > 0 && l1 > 0) {
      x += l1 / 2;
      sum += (ll)x * l0;
    }
  }

  printf("%lld\n", sum);

  return 0;
}