#include <string>
#include <vector>
#include <list>
#include <cmath>
#include <algorithm>
#include <map>
#include <set>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
using namespace std;

class Solution {
public:
    long long zeroFilledSubarray(vector<int>& nums);
};


long long Solution::zeroFilledSubarray(vector<int>& nums)
{
  long long num_zeros;
  size_t i;
  long long rv;

  num_zeros = 0;
  rv = 0;

  for (i = 0; i < nums.size(); i++) {
    if (nums[i] == 0) {
      num_zeros++;
    } else {
      num_zeros = 0;
    }
    rv += num_zeros;
  }
 
  return rv;
}

int main()
{
  vector <int> nums;
  int i;
  Solution s;

  while (cin >> i) nums.push_back(i);
  cout << s.zeroFilledSubarray(nums) << endl;
}