Quality check

/* The isBadVersion API is defined in the parent class VersionControl.
      boolean isBadVersion(int version); */

public class Solution extends VersionControl {
    public int firstBadVersion(int n) {
        int f = 0;
        int b = n-1;
        int ans = 0;

        while (f <= b) {
            int m = (f + b) / 2;
            boolean x = isBadVersion(m+1);
            if (x == true) {
                b = m-1;
                ans = m+1;
                System.out.println(ans);
            } else {
                f = m+1;
            }
        }
        return ans;
    }
}