void input(char str[]){
 gets(str);
}

void display(char str[]){
 int i;
 for(i=0;str[i]!='\0';i++)
  printf("%c ",str[i]);
 printf("\n");
}

int countA(char str[]){
 int i,count=0;
 for(i=0;str[i]!='\0';i++){
  if(str[i]=='a'||str[i]=='A')
   count++;
 }
 return count;
}

int findItem(char array[],int size,char item){
 int i,found=0;
 for(i=0;array[i]!='\0';i++){
  if(array[i]==item){
   found=1;
   break;
  }
 }
 return found;
}

int isPalindrome(char str1[]){
 int i,size=strlen(str1)-1;
 int yes=1;
 for(i=0,j=size-1;i<=size/2;i++,j--){
  if(str1[i]!=str1[j]){
   yes=0;
   break;
  }
 }
 return yes;
}

int countVowel(char str[]){
 int i,count=0;
 for(i=0;str[i]!='\0';i++){
  //val=toupper(str[i]);
  //if(val=='A'||val=='E'||val=='I'||val=='O'||val=='U')
  if(str[i]=='a'||str[i]=='A'||str[i]=='e'||str[i]=='E'
||str[i]=='i'||str[i]=='I'||str[i]=='o'||str[i]=='O'||str[i]=='u'||str[i]=='U')
   count++;
 }
 return count;
}

MAIN CODE
#include<stdio.h>
#include"strings.h"

int main(void){
 char string1[30]="hello world";
 input(string1);
 display(string1);
 printf("%d\n",countA(string1));
 return 0;
}