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#include <iostream>
#include <set>
#include <unordered_map>
#include <cstdint>
#include <vector>
#include <numeric>


using namespace std;


struct Elem
{
	int32_t m_iNum;
	int32_t m_iMaxLenSoFar;

	unordered_map<int32_t, int32_t>  m_umJump2MaxLen;

	bool operator<(int32_t iNum) const
	{
		return m_iNum < iNum;
	}

	void Update(int32_t iJump, int32_t iMaxLen)
	{
		if (m_umJump2MaxLen.size() == 0)
		{
			m_umJump2MaxLen[iJump] = iMaxLen;
			m_iMaxLenSoFar = iMaxLen;
			return;
		}

		if (m_umJump2MaxLen.count(iJump) == 0 || m_umJump2MaxLen[iJump] < iMaxLen)
		{
			m_umJump2MaxLen[iJump] = iMaxLen;
		}

		if (iMaxLen > m_iMaxLenSoFar)
			m_iMaxLenSoFar = iMaxLen;
	}
};


static size_t iCnt, iGoodInVectCnt;

static set<int32_t>::const_iterator itSet;

static set<int32_t> setNumbers;

static vector<Elem> vElems;


static inline void MakeUpdate(int32_t iNum)
{
	int iMyIndex = (int) iGoodInVectCnt;

	Elem & el2Update = vElems[iMyIndex];

	el2Update.m_iNum = iNum;
	el2Update.m_umJump2MaxLen.clear();
	el2Update.m_iMaxLenSoFar = 1;

	if (iMyIndex == 0)
		return;

	if (iMyIndex == 1)
	{
		int32_t iJump = iNum - vElems[0].m_iNum;

		if (iJump == 1)
			return;

		el2Update.m_iMaxLenSoFar = 2;
		el2Update.m_umJump2MaxLen[iJump] = 2;
		return;
	}

	for (int iLowerIndex = iMyIndex - 1; iLowerIndex >= 0; --iLowerIndex)
	{
		const Elem & elLower = vElems[iLowerIndex];

		int32_t iJump = iNum - elLower.m_iNum;

		if (iJump == 1)
			continue;

		el2Update.Update(iJump, 2);

		for (auto itLower = elLower.m_umJump2MaxLen.begin(); itLower != elLower.m_umJump2MaxLen.end(); ++itLower)
		{
			int32_t iLowerJump = itLower->first;
			int32_t iLowerLen  = itLower->second;

			int32_t iGcd = gcd(iJump, iLowerJump);

			if (iGcd == 1) continue;

			el2Update.Update(iGcd, iLowerLen + 1);
		}
	}

	if (vElems[iMyIndex - 1].m_iMaxLenSoFar > el2Update.m_iMaxLenSoFar)
	{
		el2Update.m_iMaxLenSoFar = vElems[iMyIndex - 1].m_iMaxLenSoFar;
	}
}


static inline void MakeUpdateLoop()
{
	for (; itSet != setNumbers.end(); ++itSet, ++iGoodInVectCnt)
	{
		MakeUpdate(*itSet);
	}
}


static inline void FindUpdatePositions(int32_t iNum)
{
	itSet = setNumbers.lower_bound(iNum);

	auto itVect = lower_bound(vElems.begin(), vElems.end(), iNum);

	if (itVect == vElems.end())
	{
		iGoodInVectCnt = iCnt;
	}
	else
	{
		iGoodInVectCnt = itVect - vElems.begin();
	}
}


static void InsertNumber(int32_t iNum)
{
	setNumbers.insert(iNum);

	FindUpdatePositions(iNum);
	iCnt++;

	if (vElems.size() < setNumbers.size())
	{
		vElems.resize(vElems.size() + 1);
	}

	MakeUpdateLoop();
}


static void DeleteNumber(int32_t iNum)
{
	iCnt--;
	setNumbers.erase(iNum);

	FindUpdatePositions(iNum);

	if (vElems.size() > setNumbers.size())
	{
		vElems.resize(vElems.size() - 1);
	}

	MakeUpdateLoop();
}


static inline void DoOp(int32_t iNum)
{
	if (setNumbers.count(iNum) == 0)
	{
		InsertNumber(iNum);
	}
	else
	{
		DeleteNumber(iNum);
	}
}


static inline int GetAnswer()
{
	if (iCnt <= 2)
		return (int) iCnt;

	return vElems.back().m_iMaxLenSoFar;
}


int main()
{
	int iDummy, iOpCnt, iNum;

	// freopen("sample_input.txt", "r", stdin);
	// freopen("sample_output.txt", "w", stdout);

	cin >> iDummy >> iOpCnt;

	iCnt = 0;

	for (int i = 1;; ++i)
	{
		cin >> iNum;

		DoOp(iNum);

		int iAnswer = GetAnswer();

		cout << iAnswer;

		if (i == iOpCnt) break;

		cout << endl;
	}
}