1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
#define pii pair<int,int>
#define vii vector<pair<int,int>>
#define vi vector<int>
#define pll pair<ll, ll>
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define count_bits(x) __builtin_popcountll((x))
const ll M = 1e9+7;
const ll INF = 1e9;
//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));}
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

unordered_set<int> akt;

const int MAXN = 1e7 + 5;

int cnt[MAXN];
vi primes;

int wyn(int n){
    if(siz(akt) == 0) return 0;
    int mx = (siz(akt) != 0 ? 1 : 0);
    for(auto k : primes){
        if(k > 2 * n / siz(akt)) break;
        int tmp = 0;
        for(auto u : akt){
            cnt[u % k]++;
            tmp = max(tmp, cnt[u%k]);
        }
        mx = max(mx, tmp);
        for(auto u : akt){
            cnt[u%k]=0;
        }
    }
    return mx;
}

int last[MAXN]; 

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    for(ll i = 2; i <= n+1; ++i){
        if(last[i] != 0) continue;
        last[i] = i;
        primes.push_back(i);
        for(ll j = i * i; j <= n+1; j += i){
            last[j] = i;
        }
    }

    int q;
    cin >> q;
    int a;
    for(int i = 0; i < q; ++i){
        cin >> a;
        if(akt.find(a) != akt.end()){
            akt.erase(a);
        }
        else{
            akt.insert(a);
        }
        cout << wyn(n) << "\n";
    }
    return 0;
}