#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;
using ull = unsigned long long;

template<class T> inline bool chmax(T& a, T b)
{
	if (a < b)
		a = b;
	return a < b;
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	ll d, q;
	cin >> d >> q;
	vector<ll> a(q), b(q);
	set<ll> s;
	for (ll i = 0; i < q; ++i)
	{
		cin >> a[i] >> b[i];

		s.insert(a[i] - 1);
		s.insert(a[i]);
		s.insert(b[i]);
		s.insert(b[i] + 1);
	}

	stringstream ss;
	ll maxd{ 0 };
	for (int i = 0; i < q; ++i)
	{
		auto itb = s.lower_bound(a[i]);
		auto ite = s.upper_bound(b[i]);
		ite = s.erase(itb, ite);
		auto it = ite;
		chmax(maxd, *ite - *(--it) - 1);
		ss << maxd << "\n";
	}

	cout << ss.str();

	return 0;
}