#include<stdio.h>
int countvowels(char str[]);

int main() {
    char str[]="hello world";
    printf("vowels are : %d",countvowels(str));
} 

int countvowels(char str[]){
   int count=0;
   
   for(int i=0;str[i]!='\0';i++){
       if(str[i]=='a'|| str[i]=='e' || str[i]=='i' || str[i]=='o' || str[i]=='u'){
           count++;
       }
   }
   return count;
}