#include 
#include 
void main()
{
    char c;
    printf("Enter u to display alphabets in uppercase. And enter l to display alphabets in lowercase: ");
    scanf("%c", &c);
   
 if(c== 'U' || c== 'u')
    {
       for(c = 'A'; c <= 'Z'; ++c)
         printf("%c ", c);
    }
    else if (c == 'L' || c == 'l')
    {
      for(c = 'a'; c <= 'z'; ++c)
      printf("%c ", c);
    }
    else
       printf("Error! You entered invalid character.");
   getch();

}