I need help - Codeforces

I am getting MLE for this problem and I can't figure it out. Any help would be appreciated:↵
https://codeforces.com/problemset/problem/1775/D↵
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<spoiler summary="Spoiler">↵
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#pragma GCC optimize("Ofast,unroll-loops")↵
#pragma GCC target("avx,avx2,fma")↵
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#include <bits/stdc++.h>↵
using namespace std;↵
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const int MAX = 3e5 + 2;↵
const int oo = 3e5;↵
vector<int> a[MAX * 2];↵
int b[MAX], dist[MAX * 2], visited[MAX * 2], pre[MAX * 2], n, s, t, cnt;↵
vector<int> res;↵
↵
void BFS(int u) {↵
    for (int i = 1; i <= oo * 2; i++) {↵
        dist[i] = -1;↵
        pre[i] = -1;↵
    }↵
    dist[u] = 0;↵
    queue<int> q;↵
    q.push(u);↵
    visited[u] = 1;↵
    while (!q.empty()) {↵
        int x = q.front();↵
        q.pop();↵
        for (auto i : a[x]) {↵
            if (visited[i] == 0) {↵
                visited[i] = 1;↵
                pre[i] = x;↵
                dist[i] = dist[x] + 1;↵
                q.push(i);↵
            }↵
        }↵
    }↵
}↵
↵
void solve() {↵
    cin >> n;↵
    for (int i = 1; i <= n; i++) {↵
        cin >> b[i];↵
        for (int j = 2; j <= int(sqrt(b[i])); j++) {↵
            if (b[i] % j == 0) {↵
                a[j + oo].push_back(i);↵
                a[i].push_back(j + oo);↵
                if (j * j != b[i]) {↵
                    a[b[i] / j + oo].push_back(i);↵
                    a[i].push_back(b[i] / j + oo);↵
                }↵
            }↵
        }↵
        if (b[i] != 1) {↵
            a[b[i] + oo].push_back(i);↵
            a[i].push_back(b[i] + oo);↵
        }↵
    }↵
    cin >> s >> t;↵
    BFS(s);↵
    if (visited[t] == 0) {↵
        cout << -1;↵
        return;↵
    }↵
    /*for (int i = 1; i <= n; i++) cout << pre[i] << " ";↵
    cout << "\n";*/↵
    /*for (int i = int(3e5) + 1; i <= int(3e5) + 20; i++) {↵
        for (auto j : a[i]) cout << j << " ";↵
        cout << "\n";↵
    }*/↵
    int k = t;↵
    cnt = 1;↵
    res.push_back(k);↵
    while (pre[k] != -1) {↵
        k = pre[k];↵
        cnt++;↵
        if (cnt % 2 == 1) res.push_back(k);↵
    }↵
    cout << res.size() << "\n";↵
    reverse(res.begin(), res.end());↵
    for (int i = 0; i < res.size(); i++) cout << res[i] << " ";↵
}↵
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int main() {↵
ios_base::sync_with_stdio(false);↵
cin.tie(0); cout.tie(0);↵
solve();↵
}↵
~~~~~↵
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</spoiler>↵
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