using System;
using System.Collections.Generic;
using System.Linq;

// https://yukicoder.me/problems/no/3015
class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("10110110");
            //3
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("0000000010000001111");
            //0
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        string S = InputList[0];
        List<RunLen.RunLenInfo> RunLenList = RunLen.DeriveRunLenInfoList(S);

        long Answer = 0;
        long BCnt = 0;
        for (int I = RunLenList.Count - 1; 0 <= I; I--) {
            if (RunLenList[I].AppearChar == '0') {
                BCnt += RunLenList[I].RunLen;
            }
            if (RunLenList[I].AppearChar == '1') {
                long Div2 = RunLenList[I].RunLen / 2;
                Answer += Div2 * BCnt;
            }
        }
        Console.WriteLine(Answer);
    }
}

#region RunLen
// ランレングス圧縮(文字列)
internal class RunLen
{
    // ランレングス圧縮情報
    internal struct RunLenInfo
    {
        internal char AppearChar;
        internal int RunLen;
    }

    // ランレングス圧縮結果を返す
    internal static List<RunLenInfo> DeriveRunLenInfoList(string pBaseStr)
    {
        var WillReturn = new List<RunLenInfo>();

        int StrUB = pBaseStr.Length - 1;
        char PrevChar = pBaseStr[0];
        int StrLen = 0;
        for (int I = 0; I <= StrUB; I++) {
            if (pBaseStr[I] != PrevChar) {
                RunLenInfo WillAdd;
                WillAdd.AppearChar = PrevChar;
                WillAdd.RunLen = StrLen;
                WillReturn.Add(WillAdd);
                StrLen = 0;
                PrevChar = pBaseStr[I];
            }
            StrLen++;

            if (I == StrUB) {
                RunLenInfo WillAdd;
                WillAdd.AppearChar = pBaseStr[I];
                WillAdd.RunLen = StrLen;
                WillReturn.Add(WillAdd);
            }
        }
        return WillReturn;
    }
}
#endregion