A program to find Armstrong numbers below given number

#include <stdio.h>
 
void main()
{
    int l, k = 1, q, r, sum = 0;
 
    printf("Enter a number: ");
    scanf("%d", &l);
 
    printf("Armstrong numbers below %d are:\n", l);
 
    while (k <= l)
    {
        q = k;
        sum = 0;
        while (q > 0)
        {
            r = q % 10;
            sum = (r * r * r) + sum;
            q = q / 10;
        }
 
        if (sum == k)
        {
            printf("\t%d", sum);
        }
        k++;
    }
 
    printf("\n");
}