I have got this code but am not totally understanding what the errors. Could someone Please help. Thanks in advance!

import java.util.Random; import java.util.Scanner; private static int nextInt() {

public class MatchingPair{ private static class input {

private static int nextInt() {
  throw new UnsupportedOperationException("Not yet implemented");
}
  Scanner sc = new Scanner(System.in);
  int randomNumber = new Random().nextInt(100) + 1; // this is wrong it should be like this: int randomNumber = (int) (Math.random() * 100 + 1); close though.
  System.out.print("Enter number to guess: ");
  int num=input.nextInt();
  while(num!=randomNumber){
      if (num>randomNumber){
          System.out.println("Guess lower!"); // this says to guess lower
    }  
      else if (num<randomNumber);
          System.out.println("Guess higher!"); // this says to guess higher
          System.out.print("Wrong! Again Guess: "); // this doesn't need to be here
          num=input.nextInt();
  }
  if (num==randomNumber){
     System.out.println("Correct!!!!!!!");


}


  }

}