#include<iostream>
#include<fstream>
#include<string>

using namespace std;

#define INPUT "input.txt"
#define OUTPUT "output.txt"

struct Monomial
{
    int exponent, multiplier = 0;
    Monomial* next = NULL;
    Monomial* last = NULL;
};

int split(string line, Monomial* pX)
{
    cout << line << "\n";

    int pos, sign, multiplier, exponent;
    bool find = false;

    if ((pos = line.find("x") != (-1)))
    {

        if (line[0] == '-')
            sign = (-1);
        else
            sign = 1;

        if ((line[0] == '-') || (line[0] == '+'))
            line.erase(0, 1);

        pos = line.find("x");
        if (pos != (-1))
        {
            if (pos == 0)
                multiplier = sign;
            else
                multiplier = sign * (stoi(line.substr(0, pos)));

            if (line != "x")
            {
                pos = 0;
                pos = line.find("^");
                if (pos == (-1))
                    exponent = 1;
                else
                    exponent = stoi(line.substr(pos + 1));
            }
            else
                exponent = 1;
        }
        else
        {
            if ((line != ""))
                multiplier = sign * stoi(line);
            else multiplier = sign;
            exponent = 0;
        }
    }
    else
    {
        exponent = 0;
        multiplier = stoi(line);
    }


    cout << multiplier << "\n";
    cout << exponent << "\n";

    while (find == false)
    {
        if (pX->exponent == exponent)
        {
            pX->multiplier += multiplier;
            find = true;
            cout << "^^^^^^^^^^^^^" << "\n";
            cout << pX->multiplier << "\n";
            cout << pX->exponent << "\n";
            cout << "^^^^^^^^^^^^^" << "\n";
        }
        else
        {
            if (pX->next != NULL)
            {
                pX = pX->next;
            }
            else
            {
                pX->next = new Monomial;
                pX->next->exponent = exponent;
                pX->next->multiplier += multiplier;
                pX->next->last = pX;
                //pX = pX->next;
                find = true;
            }
        }
    }

    return pX->exponent;

}


void sort(Monomial* pX)
{
    int ex, mult;
    Monomial* firstPX = pX;
    Monomial* buf;
    bool check = false;
    while (check == false)
    {
        pX = firstPX;
        while (pX->next != NULL)
        {

            if (pX->exponent < pX->next->exponent)
            {
                ex = pX->exponent;
                mult = pX->multiplier;
                pX->exponent = pX->next->exponent;
                pX->multiplier = pX->next->multiplier;
                buf = pX->next->last;
                pX->next->last = pX;
                pX->last = buf;
                pX->next->exponent = ex;
                pX->next->multiplier = mult;
            }
            pX = pX->next;

        }
        pX = firstPX;
        check = true;
        while (pX->next != NULL)
        {
            if (pX->exponent < pX->next->exponent)
                check = false;
            pX = pX->next;
        }
    }

    pX = firstPX;
    while (pX != NULL)
    {
        cout << "0000000000000" << "\n";
        cout << pX->multiplier << "\n";
        cout << pX->exponent << "\n";
        cout << "0000000000000" << "\n";
        pX = pX->next;
    }
}


void main()
{
    char ch;
    string line;
    int max = 0, pMax = 0;

    Monomial* pX = new Monomial;
    pX->exponent = 0;
    Monomial* lastPX = pX;


    std::fstream file;
    file.open(INPUT);

    if (file.is_open())
    {
        if (!file.eof())
            ch = file.get();

        while (!file.eof())
        {
            line = line + ch;
            ch = file.get();
            if ((ch == '+') || (ch == '-') || file.eof())
            {
                try {
                    pMax = split(line, pX);
                }
                catch (const exception error)
                {
                    cout << "ERROR";
                    return;
                }
                if (pMax > max)
                    max = pMax;
                cout << "===============" << "\n";
                line = "";
            }
        }
    }
    file.close();

    cout << "da"<<"\n";
    sort(pX);
    //while (lastPX->exponent < max)
    lastPX = pX;



    file.open(OUTPUT, ios_base::out | ios_base::trunc);
    if (file.is_open())
    {
        line = "";
            while (lastPX->next != 0)
            {
                if (lastPX->multiplier > 0)
                    if (lastPX->multiplier > 1) line = line + "+" + to_string(lastPX->multiplier) + "x" + "^" + to_string(lastPX->exponent);
                    else line = line + "+" + "x" + "^" + to_string(lastPX->exponent);
                if (lastPX->multiplier < 0)
                    if (lastPX->multiplier < (-1)) line = line + to_string(lastPX->multiplier) + "x" + "^" + to_string(lastPX->exponent);
                    else line = line + "-" + "x" + "^" + to_string(lastPX->exponent);
                lastPX = lastPX->next;
            }

            if (lastPX->multiplier > 0)
                line = line + "+" + to_string(lastPX->multiplier);
            if (lastPX->multiplier < 0)
                line = line + to_string(lastPX->multiplier);
        if (line[0] == '+') line.erase(0, 1);
        cout << line;
        file << line;
    }

    file.close();
}