#include <iostream>
using namespace std;

class LongInt // class declaration section
{
public:
    LongInt();
    LongInt(int[], int);
    void print() const;
    void read();
    LongInt add(LongInt) const;
    LongInt substract(LongInt) const;

private:
    int *a;
    int length;

};

LongInt::LongInt() { //Class implementation section
    a = new int [5000];
    length = 5000;
    for(int i=0;i<length;i++)
           a[i]=0;
}

LongInt::LongInt(int num[], int l) {
    a = new int[5000];
    length = l;
    for(int i=0;i<length;i++)
        a[i]=num[i];
}

void LongInt::print() const {
    bool nozero = false ;
       //mycode
    for(int i=0;i<length;i++) {
        if(a[i] == 0 && nozero == false) {
            nozero = false;
        }
        else {
            nozero = true;

        cout << a[i];
        }
    }
    cout << endl;
}

void LongInt::read() {
    char c;
    cin.get(c);
    int l = 0;
    while (c != '+' && c != '-' && c != '$') {
        if('0' <= c && c <= '9')
            a[l++] = c - '0';
        cin.get(c);
    }
    length = l;
    }

LongInt LongInt::add(LongInt other) const {
    LongInt result;
    //Make length of result +1 of largest of both integers
    result.length = ((length>other.length) ? length : other.length) + 1;
    result.a = new int [result.length];
    int carry = 0; //initial carry is 0
    int p1 = length - 1;
    int p2 = other.length - 1;
    int p3 = result.length - 1;
    for (int i=p3; i>0; i--) {
        result.a[p3] = carry;
        if (p1 >= 0) {
            result.a[p3] = result.a[p3] + a[p1];
            p1--;
        }
        if (p2 >= 0) {
            result.a[p3] = result.a[p3] + other.a[p2];
            p2--;
        }
        carry = (result.a[p3])/10;
        result.a[p3] = (result.a[p3])%10;
        p3--;
        }
    //last carry
    result.a[p3] = carry;
    return result;
}

LongInt LongInt::substract(LongInt other) const {
    LongInt result;
    //Make length of result -1 of largest of both integers
    result.length = ((length > other.length) ? length : other.length);
    result.a = new int [result.length];
   /* int carry = 0; //initial carry is 0 */
    int p1 = length - 1;
    int p2 = other.length - 1;
    int p3 = result.length - 1;
    for (int i=p3; i>0; i--) {
        if (other.a[p2] > a[p1]) { a[p1] = a[p1] + 10;
            a[p1-1] = a[p1-1] -1 ;

            result.a[p1] = a[p1] - other.a[p2];
        }
        else {
            result.a[p1] = a[p1] - other.a[p2];

        }

        /*result.a[p3] = carry;
        if (p1 >= 0) {
            result.a[p3] = result.a[p3] + a[p1];
            p1--;
        }
        if (p2 >= 0) {
            result.a[p3] = result.a[p3] - other.a[p2];
            p2--;
        }
        carry = (result.a[p3] +10);
        result.a[p3] = (result.a[p3]) -10;
        p3--;*/

        p1--;
        p2--;
        p3--;
            }


    return result;
    //my code
}

//client code to test the functinoality of the class LongInt
int main() {
    LongInt I1,I2,I3,I4,I5;
    I1.read();
    cout << "First Integer is ";
    I1.print();
    I2.read();
    cout << "Second integer is: ";
    I2.print();
    I3.read();
    cout << "Third Integer is: " ;
    I3.print();

    I4 = I2.add(I1); //add them
    cout << "\nFirst + Second is: " << endl;
    I4.print();

    I5 = I4.substract(I3); // substrect I4 - I3
    cout << "\nTotal - Third is: " << endl;
    I5.print();

    return 0;
}