class PQ{
private:
int *arr;
int capacity;
int size = 0;

PQ(const PQ& other) {}
PQ& operator=(const PQ& other) {}

public:
PQ(int cap):capacity(cap){
    arr = new int [++capacity];
    for (int i= 0; i <= capacity; i++)      arr[i] = {0};
}

~PQ(){
    delete []arr;
}

int top(){
    return arr[1];
}
void pop(){
    arr[1] = arr[size];
    size--;
    int idx = 1;
    int childidx;

    while (2*idx < size && (arr[idx] < arr[2*idx] || arr[idx] < arr[2*idx+1])){
        if (arr[2*idx] > arr[2*idx+1]) childidx = 2*idx;
        else childidx = 2*idx+1;

        int temp = arr[idx];
        arr[idx] = arr[childidx];
        arr[childidx] = temp;
        idx = childidx;
    }
}

void push(int data){
    arr[++size] = data;
    int idx = size;
    while(arr[idx] > arr[idx/2] && idx/2 !=0 ) { // && stop when arr[0] reached.
        int temp = arr[idx];
        arr[idx] = arr[idx/2];
        arr[idx/2] = temp;
        idx = idx/2;
    }
}

bool empty(){
    return !size;
}