#include <iostream>
#include <queue>
#include <forward_list>
using namespace std;

bool checkQueue(queue<int> q,int x) {
    int position = 0;
    bool check = true;
    int i = 0;
    unsigned int size = q.size();
    while (!q.empty()) {
        if (q.front() == x) {
            if (check == true) {
                position = i;
                check = false;
            }
            else if (i == size - 1 - position) {
                return true;
            }
        }
        i++;
        q.pop();
    }
    return false;
}

void eraseQueue(forward_list<queue<int>>& list, int x) {
    auto it = list.before_begin();
    auto next = list.begin();
    while (next != list.end()) {
        if (checkQueue(*next, x)){
            next = list.erase_after(it);
      }
        else {
            it++;
            next++;
        }
    }
}
int main() {
    queue<int> q;
    int a = 2;
    q.push(4);
    q.push(2);
    q.push(3);
    q.push(2);
    q.push(9);
    queue<int> q2;
    q2.push(7);
    q2.push(8);
    q2.push(9);
    queue<int> q3;
    q3.push(1);
    q3.push(2);
    q3.push(3);
    q3.push(1);
    forward_list<queue<int>> list;
    list.push_front(q);
    list.push_front(q2);
    list.push_front(q3);
    eraseQueue(list, a);
    auto it = list.begin();
    while (it != list.end()) {
        while (!it->empty()) {
            cout << it->front() << " ";
            it->pop();
        }
        cout << endl;
        it++;
    }
    return 0;
}