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#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

////// kod pochodzi z tego bloga: https://codeforces.com/blog/entry/62393
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};
///////

pii jump[10000001];
int prime_num[10000001];
unordered_map<ll,int,custom_hash> modulos;
unordered_set<ll,custom_hash> czy_mam[1000001];
int modulos2[50][250];

int rel_prime[700000];
int is[10000001];
vi opers;
int n,q;

int ans_cnt[1000003];
int cur_ans = 0;
vi cur_vect;

void add_pair(int a, int b)
{
    int d = abs(opers[a]-opers[b]);
    while(d > 1 && jump[d].ff != -1)
    {
        int p = jump[d].ff;
        if(czy_mam[a].find(p) == czy_mam[a].end()) 
        {
            ans_cnt[++modulos[p+(opers[a]%rel_prime[p])*1e9]]++;
            czy_mam[a].insert(p);
        }
        if(czy_mam[b].find(p) == czy_mam[b].end()) 
        {
            ans_cnt[++modulos[p+(opers[b]%rel_prime[p])*1e9]]++;
            czy_mam[b].insert(p);
        }
        d = jump[d].ss;
    }
}

void add_num(int ind)
{
    rep(i,siz(cur_vect))
    {
        if(is[opers[cur_vect[i]]] != cur_vect[i])
        {
            swap(cur_vect[i],cur_vect[siz(cur_vect)-1]);
            cur_vect.pop_back();
            i--;
            continue;
        }
        add_pair(cur_vect[i],ind);
    }
    cur_vect.pb(ind);
    rep2(i,1,49) ans_cnt[++modulos2[i][opers[ind]%rel_prime[i]]]++;
}

void del_num(int ind)
{
    forall(it,czy_mam[ind]) ans_cnt[modulos[it+(opers[ind]%rel_prime[it])*1e9]--]--;
    rep2(i,1,49) ans_cnt[modulos2[i][opers[ind]%rel_prime[i]]--]--;
}

void fix_ans()
{
    if(cur_ans == 0) cur_ans = 1;
    if(ans_cnt[cur_ans+1] != 0) cur_ans++;
    if(ans_cnt[cur_ans] == 0) cur_ans--;
    if(cur_ans == 0) cur_ans = 1;
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    random_start();
    int cnt = 1;
    rep2(i,2,10000000)
    {
        if(jump[i].ff == 0)
        {
            rel_prime[cnt] = i;
            prime_num[i] = cnt;
            jump[i].ff = cnt;
            if((ll)i*(ll)i > 10000000) 
            {
                cnt++;
                continue;
            }
            for(int j = i*i; j <= 10000000; j+=i) jump[j].ff = cnt;
            cnt++;
        }
    }
    int x;
    int d;
    rep2(i,2,10000000)
    {
        if(jump[i].ff < 50)
        {
            jump[i].ff = -1;
            continue;
        }
        x = i;
        d = rel_prime[jump[i].ff];
        while(x%d == 0) x /= d;
        jump[i].ss = x;
    }
    cin >> n >> q;
    opers.resize(q);
    rep(i,q) 
    {
        cin >> opers[i];
        is[opers[i]] = -1;
    }
    ans_cnt[0] = 1e9;
    int ile = 0;
    rep(i,q)
    {
        if(is[opers[i]] == -1)
        {
            ile++;
            add_num(i);
            is[opers[i]] = i;
        }
        else 
        {
            ile--;
            del_num(is[opers[i]]);
            is[opers[i]] = -1;
        }
        fix_ans();
        if(ile != 0) cout << cur_ans << "\n";
        else cout << "0\n";
    }
}