Can you please explain what am I missing in this code because I am not able to clear all the test cases?
import java.util.*;
class Main {
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
int ch = sc.nextInt();
sc.nextLine();
String str = sc.nextLine();
char[] arr = str.toCharArray();
int fa = 0;
int fb = 0;
for(int i=0; i<arr.length; i++){
if(arr[i]==‘a’){
fa++;
}
else{
fb++;
}
}
if(fa>=fb){
int j=0;
for(int i=0; i<arr.length; i++){
if(arr[i]==‘b’){
arr[i]=‘a’;
fa++;
j++;
}
if(j==ch || i==arr.length-1) {
break;
}
}
System.out.println(fa);
}
else if(fb>fa){
int j=0;
for(int i=0; i<arr.length; i++){
if(arr[i]=='a'){
arr[i]='b';
fb++;
j++;
}
if(j==ch || i==arr.length-1) {
break;
}
}
System.out.println(fb);
}
}
}