#include <stdio.h>

int main(void){

char * text;
int i = 0;
text = "abababababa";

printf("Bitte eingeben\n");


for(i=0; text[i]!=0; i++){
    if(text[i]=='a' || text[i]=='e' || text[i]=='i' || text[i]=='o' || text[i]=='u')
    {
    text[i] = 'x';
   }
}
printf("%s", text);

return 0;
}