my code is not passing the two test cases i don’t know why.please tell the error
the code is
import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner scn=new Scanner(System.in);
String str=scn.nextLine();
StringBuilder sb=new StringBuilder(str);
int[]freq=new int[sb.length()];
for(int i=0;i<sb.length()-1;i++) {
freq[i]=1;
for(int j=i+1;j<=sb.length()-1;j++) {
if(sb.charAt(i)==sb.charAt(j)) {
freq[i]++;
sb.setCharAt(j,'0');
}
}
}
int max=freq[0];
int index=0;
for(int i=0;i<=freq.length-1;i++) {
if(freq[i]>max) {
max=freq[i];
index=i;
}
}
System.out.println(sb.charAt(index));
}
}