Program to add and multiply two matrix using OOP

#include
class matrix
{
    private:
    int m, z[10][10];

    public:
    int i, j, k;
    void getdata();
    {
        cout<<"Enter the order of the square matrix: "; cin>m;
        cout<<"Enter the "<<m<<"*"<<m<<" elements: "<<endl;
        for(i=0;i<m;i++)
            for(j=0;j<m;j++) cin>>z[i][j];
    }
    friend int check(matrix a, matrix b)
    {
        if(a.m == b.m)
             return 1;
        else
            return 0;
    }
    void display()
    {
        cout<<"Size is "<<m<<"*"<<m<<endl;
        for(i=0;i<m;i=+)
        {
            for(j=0; j<m; j++)
                cout<<z[i][j]<<"\t";
            cout<<endl;
                
        }
    }
    matrix sum(matrix, matrix);
    matrix product(matrix,matrix);
};
matrix matrix :: sum(matrix p, matrix q)
{
    int d, e, t;
    matrix r;
    r.m = p.m;
    t = p.m;
    for(d=0; d<t; d++)
    {
        for(e=0; e<t; e++)
        {
            r.z[d][e] = p.z[d][e] + q.z[d][e];
        }
    }
    return r;
}
matrix matrix :: product(matrix p, matrix q)
{
    matrix r;
    int f,g,h,t;
    r.m = p.m;
    t = p.m;
    for(f=0; f<t; f++)
    {
        for(g=0;g<t;g++)
        {
            r.z[f][g] = 0;
            for(h=0; h<t; h++)
            {
                r.z[f][g] = r.z[f][g] + p.z[f][h]*q.z[h][g];
            }
        }
    }
    return(r);
}
int main()
{
    matrix a, b,c, d;
    cout<<"\n Enter the details of 1st matrix: "<<endl;
    a.getdata();
    cout<<"\n Enter the details of 2nd matrix: "<<endl;
    b.getdata();
    cout<<"\n 1st Matrix:"<<endl;
    a.display();
    cout<<"\n 2nd matrix: "<<endl;
    b.display();
    int x = check(a, b);
    if(x==1)
    {
        c = c.sum(a,b);
        cout<<"\n Sum of 2 matrix: "<<endl;
        c.display();
        d = d.product(a,b);
        cout<<"\n Product of 2 matrix: "<<endl;
        d.display();
    }
    else
        cout<<"\n Addition and multiplication not possible!!\n";
        return(0);
}

OUTPUT
Enter the details of 1st matrix
Enter the order of the matrix: 2
Enter the 2*2 elements:
1
2
3
4

Enter the details of 2nd matrix
Enter the order of the matrix: 2
Enter the 2*2 elements:
4
3
1
2

1st matrix:
Size is 2*2
1   2
3   4

2nd matrix:
Size is 2*2
4    3
1   2

Sum of 2 matrix:
Size is 2*2
5   5
4   6

Product of 2 matrix:
Size is 2*2 
6   7
16  17