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#include <iostream>
#include <vector>
#include <unordered_map>
#include <climits>

using namespace std;

const int DRAWS = 80;

struct Divisors {
    int count = 0;
    int divisors[10];
};

inline long long encodeKey(int divisor, int remainder) {
    return ((long long)divisor << 32) | (unsigned int)remainder;
}
inline int keyDivisor(long long key) { return (int)(key >> 32); }
inline int keyRemainder(long long key) { return (int)(key & 0xFFFFFFFF); }

vector<int> generatePrimes(int n) {
    vector<int> primes;
    vector<bool> isPrime(n + 1, true);
    isPrime[0] = isPrime[1] = false;
    for (int i = 2; i <= n; ++i) {
        if (isPrime[i]) {
            primes.push_back(i);
            if ((long long)i * i <= n) {
                for (int j = i * i; j <= n; j += i) {
                    isPrime[j] = false;
                }
            }
        }
    }
    return primes;
}

vector<Divisors> generatePrimeDivisors(int q, const vector<int> &primes) {
    vector<Divisors> primeDivisors(q + 1);
    for (int prime : primes) {
        int number = prime;
        while (number <= q) {
            primeDivisors[number].divisors[primeDivisors[number].count++] = prime;
            number += prime;
        }
    }
    return primeDivisors;
}


int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    uint32_t rng_state = 637258367;
    auto rng = [&]() -> uint32_t { rng_state ^= rng_state << 13; rng_state ^= rng_state >> 17; rng_state ^= rng_state << 5; return rng_state; };

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

    vector<int> primes = generatePrimes(n);
    vector<Divisors> primeDivisors = generatePrimeDivisors(n, primes);

    vector<bool> stones(n + 1, false);
    int stonesCount = 0;
    vector<int> stoneList;
    vector<int> stoneIndex(n + 1, -1);

    unordered_map<long long, int> bestScores;
    int bestScore = 0;
    vector<long long> bestCandidates;
    int skipRemaining = 0;

    unordered_map<long long, int> candidates;
    candidates.reserve(DRAWS * 8);

    for (int i = 1; i <= q; ++i) {
        int stone;
        cin >> stone;
        bool adding = !stones[stone];
        if (!adding) {
            stones[stone] = false;
            stonesCount--;
            int index = stoneIndex[stone];
            stoneList[index] = stoneList.back();
            stoneIndex[stoneList.back()] = index;
            stoneList.pop_back();
            stoneIndex[stone] = -1;
        } else {
            stones[stone] = true;
            stonesCount++;
            stoneIndex[stone] = stoneList.size();
            stoneList.push_back(stone);
        }

        if (stonesCount == 0) {
            cout << 0 << '\n';
        } else if (stonesCount == 1) {
            cout << 1 << '\n';
        } else if (skipRemaining > 0) {
            skipRemaining--;
            int diff = adding ? 1 : -1;
            bool bestChanged = false;
            for (long long c : bestCandidates) {
                if (stone % keyDivisor(c) == keyRemainder(c)) {
                    bestScores[c] += diff;
                    if (diff == 1 && bestScores[c] > bestScore) {
                        bestScore = bestScores[c];
                    } else if (diff == -1 && bestScores[c] + 1 == bestScore) {
                        bestChanged = true;
                    }
                }
            }
            if (bestChanged) {
                bestScore = 0;
                for (long long c : bestCandidates) {
                    bestScore = max(bestScore, bestScores[c]);
                }
            }
            cout << bestScore << '\n';
        } else {
            candidates.clear();
            int drawBest = 0;
            for (int i = 0; i < DRAWS; ++i) {
                int start = rng() % stonesCount;
                int end = rng() % stonesCount;
                if (start == end) {
                    continue;
                }
                int distance = abs(stoneList[end] - stoneList[start]);
                for (int i = 0; i < primeDivisors[distance].count; ++i) {
                    int divisor = primeDivisors[distance].divisors[i];
                    int remainder = stoneList[start] % divisor;
                    long long key = encodeKey(divisor, remainder);
                    candidates[key]++;
                    drawBest = max(drawBest, candidates[key]);
                }
            }
            bestCandidates.clear();
            for (const auto &[key, count] : candidates) {
                if (count >= drawBest - 100) {
                    bestCandidates.push_back(key);
                }
            }

            bestScores.clear();
            bestScore = 0;
            int worstScore = INT_MAX;
            for (int s : stoneList) {
                for (long long c : bestCandidates) {
                    if (s % keyDivisor(c) == keyRemainder(c)) {
                        bestScores[c]++;
                        bestScore = max(bestScore, bestScores[c]);
                    }
                }
            }
            for (long long c : bestCandidates) {
                worstScore = min(worstScore, bestScores[c]);
            }
            bestScore = max(bestScore, 1);
            skipRemaining = max(0, (bestScore - worstScore) / 2);
            cout << bestScore << '\n';
        }
    }
}