import java.util.NoSuchElementException;

class IntegerStack {

	private int[] stack = null;
	private int size = 0;

	IntegerStack(int length) {
		stack = new int[length];
	}

	void push(int elm) {
		if (size < stack.length) {
			stack[size++] = elm;
		}
	}

	int pop() {
		if (size > 0) {
			return stack[--size];
		}
		throw new NoSuchElementException();
	}

	int size() { return size; }

	@Override
	public String toString() {
		if (size == 0) {
			return "()";
		}

		String str = "(";
		for(int i = 0; i < size - 1; i++) {
			str += stack[i] + ","; 
		}
		str += stack[size - 1] + ")";
		return str;
	}

	@Override
	public boolean equals(Object obj) {
		if (!(obj instanceof IntegerStack)) {
			return false;
		}
	
		IntegerStack is = (IntegerStack) obj;

		if (this.size() != is.size()) {
			return false;
		}

		for(int i = 0; i < size; i++) {
			if (this.stack[i] != is.stack[i]) {
				return false;
			}
		}
		return true;
	}

} // end of class