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#include <bits/stdc++.h>

using namespace std;

int PRIMES[] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61,
    67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137,
    139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211,
    223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283,
    293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379,
    383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461,
    463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563,
    569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643,
    647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739,
    743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829,
    839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937,
    941, 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021,
    1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093,
    1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181,
    1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259,
    1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321,
    1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433,
    1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493,
    1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579,
    1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657,
    1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741,
    1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831,
    1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913,
    1931, 1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997, 1999, 2003,
    2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083, 2087,
    2089, 2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161,
    2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243, 2251, 2267, 2269,
    2273, 2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339, 2341, 2347,
    2351, 2357, 2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411, 2417,
    2423, 2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531,
    2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617, 2621,
    2633, 2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687, 2689, 2693,
    2699, 2707, 2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753, 2767,
    2777, 2789, 2791, 2797, 2801, 2803, 2819, 2833, 2837, 2843, 2851,
    2857, 2861, 2879, 2887, 2897, 2903, 2909, 2917, 2927, 2939, 2953,
    2957, 2963, 2969, 2971, 2999, 3001, 3011, 3019, 3023, 3037, 3041,
    3049, 3061, 3067, 3079, 3083, 3089, 3109, 3119, 3121, 3137, 3163};


set<int> get_unique_prime_factors(int n) {
    set<int> factors;
    for (int prime : PRIMES) {
        if (prime * prime > n) {
            break;
        }
        if (n % prime == 0) {
            factors.insert(prime);
            while (n % prime == 0) {
                n /= prime;
            }
        }
    }
    if (n > 1) {
        factors.insert(n);
    }
    if (factors.count(2)) {
        factors.erase(2);
    }
    return factors;
}


vector<pair<int, int>> get_modulo(const set<int>& stones, int prime) {
    map<int, int> modulo;
    for (int stone : stones) {
        modulo[stone % prime]++;
    }
    vector<pair<int, int>> result;
    for (auto& [mod, count] : modulo) {
        result.push_back({mod, count});
    }
    sort(result.begin(), result.end(), [](pair<int, int> a, pair<int, int> b) {
        return a.second > b.second;
    });
    return result;
}


int brute(const set<int>& stones) {
    map<int, int> primes_counter;
    for (int stone1 : stones) {
        for (int stone2 : stones) {
            if (stone1 == stone2) {
                continue;
            }
            set<int> prime_factors = get_unique_prime_factors(abs(stone1 - stone2));
            for (int prime : prime_factors) {
                primes_counter[prime]++;
            }
        }
    }
    int pop = 2;
    int val = 0;
    for (auto& [prime, count] : primes_counter) {
        if (count > val) {
            val = count;
            pop = prime;
        }
    }
    vector<pair<int, int>> modulos = get_modulo(stones, pop);
    return modulos[0].second;
}

struct Counter {
    int value;
    int unknown;

    Counter(int value, int unknown) : value(value), unknown(unknown) {}
};


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

    int n, q;
    cin >> n >> q;

    vector<int> two_tracker(2, 0);
    set<int> stones;
    map<pair<int, int>, int> tracked_primes;

    for (int i = 0; i < q; i++) {
        int new_stone;
        cin >> new_stone;

        int max_iter = min(100, (int)stones.size());


        map<int, int> primes_counter;

        int operation = 1;

        if (stones.count(new_stone)) {
            two_tracker[new_stone % 2]--;
            operation = -1;
        } else {
            two_tracker[new_stone % 2]++;
        }

        if (!tracked_primes.empty()) {
            vector<pair<int, int>> to_delete;
            for (auto& [key, count] : tracked_primes) {
                int prime = key.first;
                int mod = key.second;
                if (count < 0.3 * max_iter) {
                    to_delete.push_back(key);
                } else if (new_stone % prime == mod) {
                    count += operation;
                }
            }
            for (auto& d : to_delete) {
                tracked_primes.erase(d);
            }
        }

        vector<int> sample_stones;
        if ((int)stones.size() <= max_iter) {
            sample_stones.assign(stones.begin(), stones.end());
        } else {
            vector<int> temp(stones.begin(), stones.end());
            mt19937 rng(1337);
            shuffle(temp.begin(), temp.end(), rng);
            sample_stones.assign(temp.begin(), temp.begin() + max_iter);
        }

        for (int s : sample_stones) {
            set<int> prime_factors = get_unique_prime_factors(abs(s - new_stone));
            for (int prime : prime_factors) {
                primes_counter[prime]++;
            }
        }

        if (stones.count(new_stone)) {
            stones.erase(new_stone);
        } else {
            stones.insert(new_stone);
        }

        if (!primes_counter.empty()) {
            vector<pair<int, int>> most_populars;
            for (auto& [prime, count] : primes_counter) {
                most_populars.push_back({prime, count});
            }
            sort(most_populars.begin(), most_populars.end(), [](pair<int, int> a, pair<int, int> b) {
                return a.second > b.second;
            });
            for (auto& [prime, count] : most_populars) {
                if (count + 4 > 0.4 * max_iter) {
                    vector<pair<int, int>> modulos = get_modulo(stones, prime);
                    for (auto& [mod, count] : modulos) {
                        if (count + 4 > 0.3 * max_iter) {
                            tracked_primes[{prime, mod}] = count;
                        } else {
                            break;
                        }
                    }
                } else {
                    break;
                }
            }
        }

        int max_val = 0;
        for (int val : two_tracker) {
            max_val = max(max_val, val);
        }
        for (auto& [key, count] : tracked_primes) {
            max_val = max(max_val, count);
        }
        if (stones.size() < 10) {
            if (stones.size() == 0) {
                cout << "0\n";
            } else if (stones.size() == 1) {
                cout << "1\n";
            } else if (stones.size() == 2) {
                cout << "2\n";
            } else {
                cout << max(max_val, brute(stones)) << "\n";
            }
        } else {
            cout << max_val << "\n";
        }
    }

    return 0;
}