String Array problem with random generator

So my task is to make a password generator what makes a pw for the length what the user typed in. It have to consist of numbers, alphabethical letters and symbols.

What did i do wrong? What could i improve in this code?

public class Program
{
    public static void main(String[] args) {

    Scanner sc = new Scanner(System.in);

    int pwLength;
    String charset = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ?!+#@=&/.,";
    char c;
    boolean viable = false;
    Random rnd = new Random();

    while(viable==false){

    String[] password;    
    pwLength = sc.nextInt();

    for(int i=0; i<=pwLength;i++){
        password[i]=Character.toString(charset.charAt(pwLength = sc.nextInt()));
    }

    viable=true;

    System.out.print("Your password is: " + password);
    System.out.print("Your password is " + pwLength + " character long!");
    }

    }
}