Trouble in main method

import java.io.PrintWriter;

import java.io.FileWriter;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Scanner;

public class TowersOfHanoiIteration {

class Stack {

//define variables needed to create a stack

int maxSize;

int topOfArray;

int array[];

PrintWriter out;

}

//create stack and define max size held by stack

Stack newStack(int maxSize) {

Stack stack = new Stack();

stack.maxSize = maxSize;

stack.topOfArray = -1;

stack.array = new int[maxSize];

return stack;

}

//define parameters if stack is full and if stack is empty. Return to user in either case.

boolean stackIsFull (Stack stack) {

return (stack.topOfArray == stack.maxSize -1);

}

boolean stackIsEmpty (Stack stack) {

return (stack.topOfArray == -1);

}

//remove items from stack. Will decrease stack capacity by 1.

int pop (Stack stack) {

if (stackIsEmpty(stack))

return Integer.MIN_VALUE;

return stack.array[stack.topOfArray--];

}

//add items to stack. Will increase stack capacity by 1.

void push (Stack stack, int data) {

if (stackIsFull(stack))

return;

stack.array[++stack.topOfArray] = data;

}

//movement between towers by intiation of two stacks defined as Tower1 and Tower2.

void moveBetweenTowers (Stack Tower1, Stack Tower2, char start, char next) {

int Tower1Top = pop(Tower1);

int Tower2Top = pop(Tower2);

//Tower1 is empty

if (Tower1Top == Integer.MIN_VALUE) {

push(Tower1, Tower2Top);

moveDisk (next, start, Tower2Top);

//Tower2 is empty

} else if (Tower2Top == Integer.MIN_VALUE) {

push(Tower2, Tower1Top);

moveDisk(start, next, Tower1Top);

//Occurence when disk of Tower1 is greater than disk of Tower2.

} else if (Tower1Top > Tower2Top) {

push(Tower1, Tower1Top);

push(Tower1, Tower2Top);

moveDisk(next, start, Tower2Top);

//occurence when disk of Tower2 is greater than disk of Tower1.

} else {

push(Tower2, Tower2Top);

push(Tower2, Tower1Top);

moveDisk(start, next, Tower1Top);

}

}

//disk movement defined

void moveDisk (char startTower, char nextTower, int Disk) {

System.out.println("Move disk " + Disk + " from " + startTower + " to " + nextTower);

}

void TowersOfHanoiIterative (int totalDisks, Stack Tower1, Stack stackEmpty, Stack Tower2) {

int n;

int maxMoves;

char start ='A', next = 'B', a ='C';

//if even move disk to empty Tower. Exchange labels of Towers.

if (totalDisks % 2 == 0) {

char temp = next;

next = start;

start = temp;

}

//For loop defined. Make movement of larger disks first

maxMoves = (int)(Math.pow(2, totalDisks) - 1);

for (n = totalDisks; n >= 1; n--)

push(Tower1, n);

for (n =1; n <=maxMoves; n++) {

if (n % 3 == 1)

moveBetweenTowers(Tower1,Tower2, start, next);

else if (n % 3 == 2)

moveBetweenTowers(Tower1, stackEmpty, start, a);

else if (n % 3 == 0 )

moveBetweenTowers(stackEmpty, Tower2, a, next);

}

}

public static void main (String args[]) {

int totalDisks = n;

out = new PrintWriter (new FileWriter("IterativeTowers.txt"));

System.out.println("enter number of disks");

Scanner input = new Scanner(System.in);

n=input.nextInt();

TowersOfHanoiIteration ob = new TowersOfHanoiIteration();

Stack Tower1, Tower2, stackempty;

Tower1 = ob.createStack(totalDisks);

Tower2 = ob.createStack(totalDisks);

stackEmpty = ob.createStack(totalDisks);

ob.TowersOfHanoiIterative(totalDisks, Tower1, stackEmpty, Tower2);

long start = System.nanoTime();

long end = System.nanoTime();

out.println("Total Time: " + (end- start) + " nano seconds.");

System.out.println("Execution completed");

out.close();

}

}