#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
    int main()
    {
      char litera;
      printf("Input a character: ");
      int check = scanf("%c", &litera);
      int a = litera >= 'a' && litera <='z';
      switch(litera*check*a)
      {
        case 'a':
        case 'A':
        case 'e':
        case 'E':
        case 'i':
        case 'I':
        case 'o':
        case 'O':
        case 'u':
        case 'U':
        case 'y':
        case 'Y':
          printf("vowel");
          return 0;
        case 0:
            printf("incorrect input");
            return 0;
        default:
          printf("consonant");
      }
    }