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#include <bits/stdc++.h> 
// Stack class.
class Stack {
    int *stack;
    int capacity;
    int size = 0;
public:
    
    Stack(int capacity) {
        stack = new int[capacity];
        this -> capacity = capacity;
    }

    void push(int num) {
        if (size < capacity) {
            stack[size++] = num;
        }
    }

    int pop() {
        if (size > 0)
            return stack[--size];
        else return -1;
    }
    
    int top() {
        if (size > 0)
            return stack[size-1];
        else return -1;
    }
    
    int isEmpty() {
        return size == 0;
    }
    
    int isFull() {
        return size == capacity;
    }
    
};