Program to find Sum of numbers divisible by 2 or 3 in a Matrix

#include<iostream.h>
#include<conio.h>
void sum(int a[10][10],int r,int c);
void main()
{
clrscr();
int a[10][10],r,c,i,j;
cout<<"\n\n";
cout<<"enter row and column";
cout<<"\n\n";
cin>>r;
cout<<"\n\n";
cin>>c;
cout<<"\n\n";
cout<<"enter elements";
cout<<"\n\n";
for(i=0;i<r;i++)
   {
    for(j=0;j<c;j++)
       {
        cout<<"\n";
        cin>>a[i][j];
       }
   }
sum(a,r,c);
getch();
}
void sum(int a[10][10],int r,int c)
{
 int i,j,sum=0;
 for(i=0;i<r;i++)
    {
     for(j=0;j<c;j++)
        {
         if(a[i][j]%2==0||a[i][j]%3==0)
           {
            sum=sum+a[i][j];
           }
        }
    }
cout<<"\n\n";
cout<<"sum of nos. divisible by 2 and 3 is"<<"\n\n"<<sum;
}