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#include "maklib.h"

#include "message.h"

#include <algorithm>

#include <iostream>



long long computeMaxValue();

void printMaxIfOneElement() {

    if (MyNodeId() == 0)

        std::cout << std::max(0, ElementAt(1)) << std::endl;

}

long long computeInOneProcess();



int main() {

	if (Size() < 2) 

        printMaxIfOneElement();

	else {

        auto max = computeMaxValue();

        if (MyNodeId() == 0)

		    std::cout << std::max(0LL, max) << std::endl;

    }

	

    return 0;

}



#if DEBUG

#define min_size 1

#else

#define min_size 100

#endif



long long computeMaxValue() {

    if (Size() <= min_size) {

        if (MyNodeId() == 0)

            return computeInOneProcess();

        else

            return 0;

    }



    int piecesPerProcess = Size();

    if (piecesPerProcess % NumberOfNodes() == 0)

        piecesPerProcess /= NumberOfNodes();

    else

        piecesPerProcess = (piecesPerProcess + NumberOfNodes()) / NumberOfNodes();



    long long max = 0LL;

    for (auto beg = (piecesPerProcess * MyNodeId()) + 1; beg < ((piecesPerProcess * (MyNodeId() + 1)) + 1); beg++) {

        long long sum = 0;

        for (auto end = beg; end <= Size(); end++) {

            sum += ElementAt(end);

            if (sum > max)

                max = sum;

            if (sum <= 0)

                break;

        }

    }



    if (MyNodeId() != 0) {

        PutLL(0, max);

        Send(0);

    }

    else 

    {

        for (auto i = 1; i < NumberOfNodes(); i++) {

            Receive(i);

            auto localMax = GetLL(i);

            if (localMax > max)

                max = localMax;

        }



        return max;

    }

        

    return 0;

}



long long computeInOneProcess() {

    long long max = 0LL;

    long long w = 0LL;

    for (auto i = 1; i <= Size(); i++) {

        if (w > 0)

            w += ElementAt(i);

        else

            w = ElementAt(i);



        if (w > max)

            max = w;

    }



    return max;

}