Fibonacci

import java.awt.Toolkit;
import java.awt.datatransfer.StringSelection;
import java.math.BigInteger;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        //String s1 = "656006096262142989350178033729549556642676383232336265433784409742154433804661332137484567136571199328212724757371571537299468910158925926520634267410117568569929788383355349652486489818108622969402477887141685962903374297020809706805196713227956014251877900218898169451536868965760698964216982448169886501238156520802621307753044482574180109648240541866529324983414010189670221762155494932626210505";
        //String s2 = "250572031945003272238062679321828252833825213808823514984330268366978962197341129230519532039014797883605808330899720778605308114380839942796889389428927605299078556674667262716674388794375852673649320630692741493085455843731600778404958287462585565120043104898780253688088872688246379722105843535447234778633004665956274642418148252674366749520021561386892682686265905694179065413231025238392035696";
        //System.out.println(skipStep(s1, s2));
        //System.out.println(addBig(s1, s2));
        Scanner sc = new Scanner(System.in);
        while(true){
            StringSelection ss = new StringSelection(calcFormatted(Integer.parseInt(sc.nextLine())));
            Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, null);
        }
    }

    public static BigInteger addBig(String number1, String number2){
        BigInteger num1 = new BigInteger(number1), num2 = new BigInteger(number2);
        return num1.add(num2);
    }

    public static BigInteger skipStep(String number1, String number2){
        BigInteger num1 = new BigInteger(number1), num2 = new BigInteger(number2);
        BigInteger firstStep = num1.add(num2);
        return firstStep.add(num1.max(num2)); //This skips a step in the Fibonacci sequence, by adding the bigger number twice.
    }

    public static BigInteger calc(int num){
        BigInteger num1 = new BigInteger("1"), num2 = new BigInteger("2");
        for (int x = 3; x < num; x++){
            num1 = num1.add(num2);
            x++;
            if (x == num){
                return num1;
            }
            num2 = num2.add(num1);
        }
        return num2;
    } //1 1 2 3 5 8 13 21 34

    public static String calcFormatted(int num){
        return "F(" + num + ") =\n\n" + calc(num);
    }

}