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#include <iostream>
#include <unordered_map>
#include <cstdint>


using namespace std;


typedef  int64_t  lli;


enum State
{
    CAN_BE_STARTED = 0,
    CAN_BE_EXTENDED = 1,
    IS_FINISHED = 2
};


static constexpr lli ONES_26 = (((lli) 1) << 26) - 1;


struct Params                    // Params of the recursive functions
{
    int8_t   m_StateA;
    int8_t   m_StateB;
    int8_t   m_iStartedTogether;
    int32_t  m_iPrevSumA;
    int32_t  m_iPrevSumB;

    lli GetCompact() const
    {
        lli iRet = (((lli) m_iPrevSumA) << 26) | (m_iPrevSumB & ONES_26);

        iRet = (iRet << 2) | m_StateA;
        iRet = (iRet << 2) | m_StateB;

        iRet = (iRet << 1) | m_iStartedTogether;

        return iRet;
    }
};


struct Memo   // For dynamic programming
{
    unordered_map<lli, lli> map;  // key: compact form of function Params; value: returned by recursive function
};


struct AllIntervals
{
    unordered_map<lli, int> map;  // key: sum of an interval; value: count of intervals with this sum
};


static int iNumCnt;
static lli iAnswer;

static AllIntervals allIntervals;

static int aNums[512];
static Memo aMemos[512];


static void InitAllIntervals()
{
    lli  iSum;

    for (int i = 0; i < iNumCnt; ++i)
    {
        iSum = aNums[i];

        for (int j = i; j < iNumCnt; ++j)
        {
            if (i != j)
                iSum += aNums[j];

            allIntervals.map[iSum]++;
        }
    }
}


// Find the number of intervals of given sum

static int GetNumberOfIntervalsOfGivenSum(int iSumToBeFound)
{
    if (allIntervals.map.count(iSumToBeFound) == 0)
        return 0;

    return allIntervals.map[iSumToBeFound];
}


static lli GetNumberOfTriplesRecursive(int iLevel, const Params & params);


static lli GetNumberOfTriplesWithMemo(int iLevel, const Params & params)
{
    lli iCompact = params.GetCompact();

    Memo & m = aMemos[iLevel];

    if (m.map.count(iCompact) == 1)
    {
        return m.map[iCompact];
    }

    lli iRet = GetNumberOfTriplesRecursive(iLevel, params);

    m.map[iCompact] = iRet;

    return iRet;
}


static inline void ChangeA(Params & newParams, const Params & oldParams)
{
    if (oldParams.m_StateA == CAN_BE_STARTED)
    {
        newParams.m_StateA = CAN_BE_EXTENDED;
        return;
    }

    if (oldParams.m_StateA == CAN_BE_EXTENDED)
    {
        newParams.m_StateA = IS_FINISHED;
    }
}


static inline void ChangeB(Params & newParams, const Params & oldParams)
{
    if (oldParams.m_StateB == CAN_BE_STARTED)
    {
        newParams.m_StateB = CAN_BE_EXTENDED;
        return;
    }

    if (oldParams.m_StateB == CAN_BE_EXTENDED)
    {
        newParams.m_StateB = IS_FINISHED;
    }
}


static lli GetNumberOfTriples(int iSumA, int iSumB)
{
    int iSumToBeFound = -(iSumA + iSumB);

    int iCnt = GetNumberOfIntervalsOfGivenSum(iSumToBeFound);

    if (iCnt == 0)
        return 0;

    if (iSumA == 0 && iSumB == 0)
    {
        if (iCnt >= 3)
            return iCnt - 2;

        return 0;
    }

    if (iSumToBeFound == iSumA || iSumToBeFound == iSumB)
    {
        if (iCnt >= 2)
            return iCnt - 1;

        return 0;
    }

    return iCnt;
}


static lli GetNumberOfTriplesRecursive(int iLevel, const Params & params)
{
    Params newParams;
    lli    iRet = 0;

    for (int iChange = 0; iChange < 4; ++iChange)
    {
        if (params.m_iStartedTogether != 0 && params.m_StateA == CAN_BE_EXTENDED && params.m_StateB == CAN_BE_EXTENDED && iChange == 2)
        {
            continue;   // to prevent counting the same case twice
        }

        bool fChangeA = (iChange & 1) != 0;
        bool fChangeB = (iChange & 2) != 0;

        if (fChangeA && params.m_StateA == IS_FINISHED)
            continue;

        if (fChangeB && params.m_StateB == IS_FINISHED)
            continue;

        if (fChangeA && params.m_StateA == CAN_BE_EXTENDED && params.m_StateB == IS_FINISHED)  // both would be finished then
            continue;

        if (fChangeB && params.m_StateB == CAN_BE_EXTENDED && params.m_StateA == IS_FINISHED)  // both would be finished then
            continue;

        if (!fChangeA && params.m_StateA == CAN_BE_STARTED && fChangeB && params.m_StateB == CAN_BE_STARTED)  // B cannot be started before A
            continue;

        if (fChangeA && params.m_StateA == CAN_BE_EXTENDED && fChangeB && params.m_StateB == CAN_BE_EXTENDED)  // both would be finished then
        {
            continue;
        }

        newParams = params;

        if (fChangeA && params.m_StateA == CAN_BE_STARTED && fChangeB && params.m_StateB == CAN_BE_STARTED)
        {
            newParams.m_iStartedTogether = 1;
        }

        if (fChangeA)
            ChangeA(newParams, params);

        if (fChangeB)
            ChangeB(newParams, params);

        if (newParams.m_StateA == CAN_BE_EXTENDED)
            newParams.m_iPrevSumA += aNums[iLevel];

        if (newParams.m_StateB == CAN_BE_EXTENDED)
            newParams.m_iPrevSumB += aNums[iLevel];

        if (newParams.m_StateA != CAN_BE_STARTED && newParams.m_StateB != CAN_BE_STARTED)
        {
            if (newParams.m_iStartedTogether == 0 || newParams.m_StateA == IS_FINISHED || newParams.m_StateB == IS_FINISHED)
            {
                iRet += GetNumberOfTriples(newParams.m_iPrevSumA, newParams.m_iPrevSumB);
            }
        }

        if (iLevel > 0)
        {
            iRet += GetNumberOfTriplesWithMemo(iLevel - 1, newParams);
        }
    }

    return iRet;
}


static void ReadData()
{
    cin >> iNumCnt;

    for (int i = 0; i < iNumCnt; ++i)
    {
        cin >> aNums[i];
    }
}


static lli Solve()
{
    Params params;

    params.m_StateA = CAN_BE_STARTED;
    params.m_StateB = CAN_BE_STARTED;
    params.m_iStartedTogether = 0;
    params.m_iPrevSumA = 0;
    params.m_iPrevSumB = 0;

    return GetNumberOfTriplesRecursive(iNumCnt - 1, params) / 3;
}


int main()
{
    ReadData();

    if (iNumCnt == 1)
    {
        cout << 0;
        return 0;
    }

    InitAllIntervals();

    cout << Solve();

    return 0;
}