Altering Letters

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub



        System.out.println("Number of Letters: ");
        int n = new Scanner(System.in) .nextInt();
        char[] letters = new char[n];


        Boolean low = false;
        Boolean high = false;


        for (int i = 0; i < n; i++) {
            System.out.println("Letter: ");
            char temp = new Scanner (System.in).next().charAt(0);
            if ((((int)temp) > 64) && ((int)temp < 91)) {
                low = true;
            } else if ((((int)temp) > 96) && ((int)temp < 123)) {
                high = true;
            }
            while ((low == false) && (high == false)) {
            System.out.println("New letter");
            temp = new Scanner (System.in).next().charAt(0);
            }
            letters[i] = temp;
            //System.out.println(letters[i]);
        }
        printLetter(letters);

    }

    public static void printLetter(char[] letters) {
        for (int i = 0; i < letters.length; i++) {
            if ((i+1) % 2 == 0) {
                int tempr;
                if (letters[i] > 91) {
                    tempr = (int)letters[i] - 32;
                } else {
                    tempr = (int)letters[i];
                }
                System.out.println((char)tempr);
            } else {
                int tempr;
                if (letters[i] < 91) {
                    tempr = (int)letters[i] + 32;
                } else {
                    tempr = (int)letters[i];
                }
                System.out.println((char)tempr);
            }

        }
    }
}