#include <bits/stdc++.h>
using namespace std;

#define For(i, a, b) for(int i = (a); i < (b); i++)
#define rep(i, n) For(i, 0, n)
#define rFor(i, a, b) for(int i = (a); i >= (b); i--)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()

using lint = long long;
using ld = long double;

int INF = 2000000000;
lint LINF = 1000000000000000000;

template <class T>
vector<pair<T, int>> RLE(vector<T> &v) {
    vector<pair<T, int>> res;
    for (auto x : v) {
        if (res.size() == 0 || res.back().first != x) {
            res.emplace_back(x, 1);
        } else {
            res.back().second++;
        }
    }
    return res;
}

vector<pair<char, int>> RLE(string &s) {
    vector<char> v;
    for (char &c : s) {
        v.emplace_back(c);
    }
    return RLE(v);
}

template <class T>
struct PrefixSum {
    int n;
    vector<T> s;
    
    PrefixSum() {}
    PrefixSum(vector<T> &a) : n(a.size()), s(n + 1) {
        for (int i = 0; i < n; i++) {
            s[i + 1] = s[i] + a[i];
        }
    }
   
    // [l, r)
    T prod(int l, int r) {
        assert(0 <= l && l <= r && r <= n);
        return (l == r ? T(0) : s[r] - s[l]);
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string s;
    cin >> s;
    auto rle = RLE(s);
    int sz = rle.size();
    vector<int> sum(sz, 0);
    rep(i, sz) {
        if (rle[i].first == '0') {
            sum[i] = rle[i].second;
        }
    }
    PrefixSum<int> ps(sum);
    lint ans = 0;
    rep(i, sz) {
        if (rle[i].first == '0') {
            continue;
        }
        int cnt = rle[i].second / 2;
        ans += lint(cnt) * lint(ps.prod(i + 1, sz));
    }
    cout << ans << "\n";
}