Generating Armstrong Numbers in C

#include<stdio.h>
#include<conio.h>
 
main()
{
   int r;
   long no = 0, c, res = 0, a;
 
   printf("Enter the maximum range upto which you want to find armstrong numbers ");
   scanf("%ld",&no);
 
   printf("Following armstrong numbers are found from 1 to %ld\n",number);
 
   for( c = 1 ; c <= no; c++ )
   {
      a= c;
      while( a != 0 )
      {
         r = a%10;
         res = res+ r*r*r;
         a = a/10;
      }
      if ( c == res )
         printf("%ld\n", c);
      res = 0;
   }
 
   getch();
   return 0;
}