#include <cstdlib>
#include <string>
#include <cstdio>
#include <iostream>

using namespace std;

class Queue {
public:
    // конструктор
    Queue() {
        curr = 0;
        first = 0;
    }

    ~Queue() = default;

    void push(int elem) {
        arr[curr++] = elem;
    }

    int front() {
        return arr[first];
    }

    void pop() {
        first++;
    }

    bool empty() {
        return curr == first;
    }

private:
    int curr, first;
    int arr[100000];
};