How to sum 2 matrices using '+' operator(operator overloading)?

CODE

How to sum 2 matrices using '+' operator(operator overloading)?

//Write a program to sum of 2 matrices using operator overloading…

#include<iostream>

using namespace std;

class sum

{

    int a[10][10],i,j,m,n;

public:

    void input(int x,int y)

    {

        m=x;

        n=y;

        cout<<"\n enter values:\n";

        for(i=0;i<m;i++)

        {

            for(j=0;j<n;j++)

            {

                cin>>a[i][j];

            }

        }

    }

    void operator +(sum b)

    {

        int c[10][10];

        for(i=0;i<m;i++)

        {

            for(j=0;j<n;j++)

            {

                c[i][j]=a[i][j]+b.a[i][j];

            }

        }

        for(i=0;i<m;i++)

        {

            cout<<"\n";

            for(j=0;j<n;j++)

            {

                cout<<"  "<<c[i][j];

            }

        }

    }

    void show()

    {

        for(i=0;i<m;i++)

        {

            cout<<"\n";

            for(j=0;j<n;j++)

            {

                cout<<"  "<<a[i][j];

            }

        }

    }

};

int main()

{

    sum num1,num2;

    int x,y;

    cout<<"\n enter M and N:";

    cin>>x>>y;

    num1.input(x,y);

    num2.input(x,y);

    cout<<"\n num1=\n";

    num1.show();

    cout<<"\n num2=\n";

    num2.show();

    cout<<"\n addition:\n";

    num1+num2;

}

Output:

enter M and N:2

3

 enter values:

1

2

3

4

5

6

 enter values:

7

8

9

10

11

12

 num1=

  1  2  3

  4  5  6

 num2=

  7  8  9

  10  11  12

 addition:

  8  10  12

  14  16  18