C programming for addition and subtraction of two matrices

/*Addition and subtraction of two matrices*/

#include<stdio.h>

void

main()

{

            int i,j,m,n,a[20][20],b[20][20],c[20][20],d[20][20];

            printf("enter the order of matrices:");

            scanf("%d%d",&m,&n);

            printf("enter the elements of matrix A:");

                        for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                scanf("%d",&a[i][j]);

                                    printf("\n");

                        }

                        printf("the input matrix A is:\n");

                        for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                printf("%d\t",a[i][j]);

                                    printf("\n");

                        }

                        printf("enter the elements of matrix B :");

                        for (i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                scanf("%d",&b[i][j]);

                                    printf("\n");

                        }

                        printf("the input matrix B is:\n");

                        for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                printf("%d\t",b[i][j]);

                                    printf("\n");

                        }

                        /*matrix summation*/

                        for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

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

                        }

                        printf("the summation matrix is:\n");

                        for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                printf("%d\t",c[i][j]);

                                    printf("\n");

                        }

/*subtraction*/

      for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                d[i][j]=a[i][j]-b[i][j];

                        }

                        printf("the subtraction matrix is:\n");

                        for(i=0;i<m;i++)

                        {

                                    for(j=0;j<n;j++)

                                                printf("%d\t",d[i][j]);

                                    printf("\n");

                        }

}