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#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <set>
#include <cmath>
#include <string>
#include <queue>
#include <numeric>
#include <unordered_set>
#include <unordered_map>
using namespace std;

using ll = long long;
using pii = pair<int, int>;

const int MAX = 10000000;
const int LIMIT = 500; // ?

bool T[MAX];
int isP[MAX];
int nextP[MAX];
vector<int> P;
unordered_set<int> S;
set<pii> cnt[MAX];
int n;
int smallRes;

struct bucket {
    bucket(int _k) : k(_k) {}
    void modify(int t, int v) {
        t %= k;
        heap.erase({cnt[t], t});
        cnt[t] += v;
        heap.insert({cnt[t], t});
    }
    int top() {
        return heap.empty() ? 0 : heap.begin()->first;
    }
    int k;
    set<pii, greater<>> heap;
    unordered_map<int, int> cnt;
};

void compP() {
    nextP[1] = 1;
    for (int i = 2; i < n; i++) {
        if (isP[i] == 0) {
            isP[i] = i;
            nextP[i] = 1;
            P.push_back(i);
            for (ll j = (ll)i * i; j < n; j += i) {
                isP[j] = i;
            }
        } else {

        }
    }
}

unordered_map<int, bucket> B;
set<pair<int, int>, greater<>> Bscores;

bucket& getBucket(int t) {
    auto it = B.find(t);
    if (it == B.end()) {
        it = B.insert({t, bucket(t)}).first;
    }
    return it->second;
}

int candP[MAX];
int Pind = 1;

int solveSmall(int a) {
    for (int b : S) {
        if (a == b) {
            continue;
        }
        int t = abs(a - b);
        while (t != 1) {
            int p = isP[t];
            if (candP[p] != Pind) {
                auto &bt = getBucket(p);
                Bscores.erase({bt.top(), p});
                bt.modify(a, T[a] ? 1 : -1);
                Bscores.insert({bt.top(), p});
                candP[p] = Pind;
            }
            t /= p;
        }
    }
    Pind++;
    return Bscores.empty() ? S.size() : Bscores.begin()->first + !S.empty();
}

void prepSmall() { 
    B.clear();
    Bscores.clear();
    for (int a : S) {
        for (int b : S) {
            if (a <= b) {
                continue;
            }
            int t = a - b;
            while (t != 1) {
                int p = isP[t];
                if (candP[p] != Pind) {
                    auto &bt = getBucket(p);
                    Bscores.erase({bt.top(), p});
                    bt.modify(a, T[a] ? 1 : -1);
                    Bscores.insert({bt.top(), p});
                }
                t /= p;
            }
        }
    }
    Pind++;
}

int solveBig(int a) {
    int res = 0;
    int op = 0;
    for (int p : P) {
        if (p * LIMIT > 2 * n) {
            break;
        }
        op++;
        auto &bt = getBucket(p);
        bt.modify(a, T[a] ? 1 : -1);
        res = max(res, bt.top());
    }
    return res;
}

int main() {
    int q;
    cin >> n >> q;
    compP();
    bool small = true;
    while (q--) {
        int a;
        cin >> a;
        a--;
        if (T[a]) {
            S.erase(a);
            if (!small && S.size() == LIMIT) {
                small = true;
                prepSmall();
            }
        } else {
            S.insert(a);
            if (small && S.size() == 2 * LIMIT) {
                small = false;
            }
        }
        T[a] ^= 1;
        cout << (small ? solveSmall(a) : solveBig(a)) << endl;
    }
    return 0;
}