C program to add two matrix into third matrix?

  #include <stdio.h>

main()
{
    int r, c, a[100][100], b[100][100], sum[100][100], i, j;
    printf("Enter the number of rows (between 1 and 100): n");
    scanf("%d", &r);
    printf("Enter the number of columns (between 1 and 100): n");
    scanf("%d", &c);

    printf("nEnter elements of 1st matrix:n");
    for (i = 0; i < r; ++i)
        for (j = 0; j < c; ++j)
        {
            printf("Enter element a[%d][%d]: ", i + 1, j + 1);
           scanf("%d", &a[i][j]);
        }

           printf("Enter elements of 2nd matrix:n");
        for (i = 0; i < r; ++i)
        for (j = 0; j < c; ++j)
        {
            printf("Enter element b[%d][%d]: ", i + 1, j + 1);
            scanf("%d", &b[i][j]);
        }

        // adding two matrices
        for (i = 0; i < r; ++i)
        for (j = 0; j < c; ++j)
            {
            sum[i][j] = a[i][j] + b[i][j];
            }

        // printing the result
        printf("nSum of two matrices: n");
        for (i = 0; i < r; ++i)
        for (j = 0; j < c; ++j)
        {
            printf("%d   ", sum[i][j]);
            if (j == c - 1)
            {
                printf("nn");
            }
        }
  getch();
}