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#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
vector<int>v;
bool many=false;
const ll base=1<<24;
unordered_map<ll, int> mp;
vector<int>active;
int pr;
vector<int>primes;
vector<int>szcnt;
vector<int>prdiv;
vector<int>pos;
vector<int> cnt;
vector<int>offset;
vector<int>freq;
vector<int>sieve;
int bests=0;
int bestl=0;
int n,q;
int P;
int M;
ll tonum(int p, int r) {
    return ((ll)p)*base + (ll)r;
}
pair<int,int> topair(ll num) {
    return {num/base, num%base};
}
vector<int>seenpr;

void rebuild() {
    mp.clear();
    szcnt=vector<int>(2*M+1);
    bestl=0;
    vector<int>seen;
    vector<int>t=active;
    sort(t.begin(), t.end());

    for (int i=0; i<t.size(); i++) {
        seen.clear();
        for (int j=0; j<i; j++) {
            int p = prdiv[t[i]-t[j]];
            if (p==0 or seenpr[p]) continue;
            ll num = tonum(p, t[i]%p);
            seenpr[p]=true;
            seen.push_back(p);
            mp[num]++;

        }
        for (int x : seen) seenpr[x]=false;
    }

    for (auto &[num, val] : mp) {
        val++;
        szcnt[val]++;
        bestl=max(bestl,val);
    }
}
vector<int>pcnt;
void add (int a) {

    for (int i=0; i<pr; i++) {
        int idx=offset[i]+a%primes[i];
        freq[cnt[idx]]--;
        cnt[idx]++;
        freq[cnt[idx]]++;

        bests=max(bests, cnt[idx]);
    }
    vector<int>seen;
    if (!many) {

        for (int x : active) {
            int p=prdiv[abs(a-x)];
            if (p==0) continue;
            pcnt[p]++;
            if (pcnt[p]==1)
            seen.push_back(p);

        }
        for (auto num : seen) {
                int c = pcnt[num];
                if (c>=2) szcnt[c]--;
                mp[tonum(num, a%num)]=c+1;
                szcnt[c+1]++;
                bestl=max(bestl, c+1);
            pcnt[num]=0;

        }

    }
    pos[a]=active.size();
    active.push_back(a);
    v[a]=1;

}
void rem(int a) {
    pos[active[active.size()-1]]=pos[a];
    swap(active[pos[a]], active[active.size()-1]);
    pos[a]=-1;
    v[a]=0;
    active.pop_back();
    for (int i=0; i<pr; i++) {
        int idx=offset[i] + a%primes[i];
        freq[cnt[idx]]--;
        cnt[idx]--;
        freq[cnt[idx]]++;
    }
    if (freq[bests]==0) bests--;
    vector<int>seen;
    if (!many) {

        for (int x : active) {
            int p=prdiv[abs(a-x)];
            if (p==0) continue;
            pcnt[p]++;
            if (pcnt[p]==1)
                seen.push_back(p);
        }
        for (auto num : seen) {
            int c = pcnt[num];
            szcnt[c+1]--;

            if (c>=2) {
                mp[tonum(num, a%num)]=c;
                szcnt[c]++;
            }
            else
                mp.erase(tonum(num, a%num));
            pcnt[num]=0;
        }
        if (szcnt[bestl]==0) bestl--;
    }


}
void update(int a) {
    if (v[a]==0) {
        add(a);
        if (!many and active.size()==2*M) many=true;

    }
    else {
        rem(a);
        if (many and active.size()==M) {
            rebuild();
            many=false;
        }

    }
    int res=!active.empty();
    res=max(res, bests);
    if (!many) res=max(res, bestl);
    cout<<res<<'\n';

}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin>>n>>q;
    freq=vector<int>(q+2, 0);
    P= min(n, int(2.5*sqrt(n)));
    M=2*n/P;
    prdiv=vector<int>(n+1, 0);
    sieve = vector<int>(n+1, 0);
    pcnt=vector<int>(n+1, 0);
    for (int i=2; i*i<=n; i++) {
        for (int j=i*i; j<=n; j+=i) {
            sieve[j]=i;
        }
    }
    for (int i=2; i<=n; i++) {
        int cur = i;
        while (sieve[cur]!=0) {
            cur/=sieve[cur];
        }
        if (cur>P) prdiv[i]=cur;
    }
    for (int i=2; i<=P; i++) {
        if (sieve[i]==0) primes.push_back(i);
    }
    pr=primes.size();
    offset.resize(pr);
    for (int i=0; i<pr; i++) {
        freq[0]+=primes[i];
        if (i!=0) offset[i]=offset[i-1]+primes[i-1];
    }
    if (pr>=1)
    cnt=vector<int>(offset[pr-1]+primes[pr-1]);
    seenpr=vector<int>(n+1, 0);
    v=vector<int>(n+1);
    szcnt=vector<int>(2*M+1);

    pos=vector<int>(n+1, -1);
    for (int i=0; i<q; i++) {
        int a;
        cin>>a;
        update(a);
    }
    return 0;
 }