Vowel or Consonant using Switch Case

#include<stdio.h>
int main()
{
 char letter;
 printf("enter an alphabet: ");
 scanf("%c", &letter);
 switch (letter)
 {

 case 'a':
     printf("its a vowel");
     break;
 case 'e':
    printf("its a vowel");
    break;
 case 'i':
    printf("its a vowel");
    break;
 case 'o':
    printf("its a vowel");
    break;
 case 'u':
    printf("its a vowel");
    break;
 case 'A':
     printf("its a vowel");
     break;
 case 'E':
    printf("its a vowel");
    break;
 case 'I' :
    printf("its a vowel");
    break;
 case 'O' :
    printf("its a vowel");
    break;
 case 'U' :
    printf("its a vowel");
    break;

 default:
    printf("its a consonant");
 }
    return 0;

}