c programm for matrix addition, ordinary matrix addition

Matrix addition:

#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
int a[4][4],b[4][4],c[4][4],i,j;
printf("enter the elements of matrix a");
for(i=0;i<=3;i++)
for(j=0;j<=3;j++)
scanf("%d",&a[i][j]);
printf("the first matrix is");
for(i=0;i<=3;i++)
{
printf("\n");
for(j=0;j<=3;j++)
printf("%d",a[i][j]);
}
printf("Enter the elements of second matrix");
for(i=0;i<=3;i++)
for(j=0;j<=3;j++)
scanf("%d",&b[i][j]);
printf("the second matrix is");
for(i=0;i<=3;i++)
{
printf("\n");
for(j=0;j<=3;j++)
printf("%d",b[i][j]);
}
for(i=0;i<=4;i++)
for(j=0;j<=4;j++)
c[i][j]=a[i][j] + b[i][j];
printf("the addition of matrix is");
for(i=0;i<=3;i++)
{
for(j=0;j<=3;j++)
printf("%d\t",c[i][j]);
printf("\n");
}
getch();
} 



#include<stdio.h>
#include<conio.h>


void main()
{
int a[20][20],b[20][20],c[20][20],i,j,r1,r2,c1,c2,ta,tb;
clrscr();
printf("Enter order of Matrix A: ");
scanf("d",&r1,&c1);
ta=r1*c1;
printf("\nEnter %d elements=",ta);
for(i=0;i<r1;i++)
{
for(j=0;j<c1;j++)
scanf("%d",&a[i][j]);
}
printf("\nEnter order of Matrix B: ");
scanf("d",&r2,&c2);
tb=r2*c2;
if(r1==r2 && c1==c2)
{
printf("\nEnter %d elements=",tb);
for(i=0;i<r2;i++)
{
for(j=0;j<c2;j++)
scanf("%d",&b[i][j]);
}
for(i=0;i<r1;i++)
{
for(j=0;j<c2;j++)
c[i][j]=a[i][j]+b[i][j];
}
printf("\nSum of matrix is\n");
for(i=0;i<r1;i++)
{
for(j=0;j<c2;j++)
{
printf("%d\t",c[i][j]);
}
printf("\n");
}
}
else
printf("\nAdddition is not possible pls enter same matrices");
getch();
}