#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
//#pragma warning(disable : 4996)

#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout << (x) << '\n'
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
//#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i, v.size()) cout << v[i] << ((i == v.size() - 1) ? "\n" : " ")
template <typename T1, typename T2> inline void chmin(T1& a, T2 b) {
	if (a > b) a = b;
}
template <typename T1, typename T2> inline void chmax(T1& a, T2 b) {
	if (a < b) a = b;
}
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef array<int, 3> arr3;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 998244353;
constexpr int MAX = 500050;
const double pi = acos(-1);
// constexpr double EPS = 1e-10;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;




void solve() {
	string T; cin >> T;
	int N = T.size();
	int M = 0;
	vector<int>idxs;
	REP(i, N) {
		if (T[i] == '1')M++;
		else {
			idxs.push_back(M);
		}
	}
	ll ans = 0;
	FOR(i, 1, M + 1) {
		ans += (i + 1) / 2;
	}

	vector<int>cum1(M + 1), cum0(M + 1);
	REP(i, M + 1) {
		cum1[i] = (i + 1) / 2;
		cum0[i] = i / 2;
	}
	bool sign = 1;
	vector<int>va, vb;
	for (auto x : idxs) {
		if (x % 2 == sign) {
			va.push_back(x);
			sign = !sign;
		}
		else vb.push_back(x);
	}
	int ce = 0, co = 0;
	int cnt = 0;
	vector<int> cumx(M + 1);
	for (auto x : va) {
		cumx[x]++;
		if (x % 2 == 0) {
			ans += cum1[x] + co;
			ce++;
		}
		else {
			ans += cum1[x] + ce;
			co++;
		}
		cnt++;
		if (cnt & 1) {
			ans += cum0[M] - cum0[x];
		}
		else ans += cum1[M] - cum1[x];
	}
	REP(i, M)cumx[i + 1] += cumx[i];
	vector<bool>v(M);
	REP(i, M) {
		if (i % 2 == 0)v[i] = 1;
		else v[i] = 0;
	}

	REP(i, M) {
		if (cumx[i] & 1)v[i] = !v[i];
	}
	//print_space(v);
	VREVERSE(vb);
	int las = M;
	REP(i, M + 1) {
		cum0[i] = cum1[i] = 0;
	}
	REP(i, M) {
		cum0[i + 1] = cum0[i];
		cum1[i + 1] = cum1[i];
		if (v[i])cum1[i + 1]++;
		else cum0[i + 1]++;
	}
	int c0 = 0, c1 = 0;
	for (auto x : vb) {
		int ad = cum1[x];
		c0 += cum0[las] - cum0[x];
		c1 += cum1[las] - cum1[x];
		ad += c0;
		swap(c0, c1);
		las = x;
		ans += ad;
	}
	print(ans);
}
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	//int q;
	//cin >> q;
	//while (q--)
	solve();
}


Measured memory_bytes: 8424