C program to read two r*c matrices A and B from user and print the matrix 5A+7B+9

#include<stdio.h>
#include<string.h>
int main()
{
    int i,j;
    int r,c;


    printf("enter the  value of r and c: ");
    scanf("%d%d",&r,&c);

    int A[r][c],B[r][c],sum[r][c],result[r][c];

    printf("enter elements of A\n");
    for(i=0;i<r;i++)
    {
        for(j=0;j<c;j++)
        {
            printf("A[%d][%d]", i,j);
            scanf("%d",&A[i][j]);
        }
        printf("\n");
    }
    printf("enter elements of B\n");
    for(i=0;i<r;i++)
    {
        for(j=0;j<c;j++)
        {
            printf("B[%d][%d]",i,j);
            scanf("%d",&B[i][j]);
        }
        printf("\n");
    }


    printf("displaying values of A\n");
    for(i=0;i<r;i++)
    {
        printf("\t");
        for(j=0;j<c;j++)
            printf("A[%d][%d]: %d ",i,j,A[i][j]);

        printf("\n");
    }
    printf("displaying values of B\n");
    for(i=0;i<r;i++)
    {
        printf("\t");
        for(j=0;j<c;j++)
            printf("B[%d][%d]: %d ",i,j,B[i][j]);

        printf("\n");
    }


    printf("after doing the sum\n");
    for(i=0;i<r;i++)
    {
        for(j=0;j<c;j++)
            sum[i][j] = 5*A[i][j]+7*B[i][j];
    }

    for(i=0;i<r;i++)
    {
        printf("\t");
        for(j=0;j<c;j++)
            printf("%d ", sum[i][j]);

            printf("\n");
    }

    for(i=0;i<r;i++)
    {
        for(j=0;j<c;j++)
            result[i][j]=9+sum[i][j];
    }
    printf("the final result after adding 9 to each elements\n");
    for(i=0;i<r;i++)
    {
        printf("\t");
        for(j=0;j<c;j++)
            printf("%d ", result[i][j]);

            printf("\n");
    }



}