#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
template<typename T>
struct RangeSet {
	// ReadMe:閉区間なことに注意
	// member
	set<pair<T, T>>st;
	T TINF;
	// constructor
	RangeSet(T lim) {
		TINF = lim + 1;
		st.insert({ -TINF,-TINF });
		st.insert({ TINF, TINF });
	}
	// cover check
	bool IsCovered(T l, T r) {
		auto ite = prev(st.lower_bound({ l + 1,l + 1 }));
		return ((ite->first <= l) && (r <= ite->second));
	}
	bool IsCovered(T x) { return IsCovered(x, x); }
	// get by covered
	pair<T, T> ByCovered(T l, T r) {
		auto ite = prev(st.lower_bound({ l + 1,l + 1 }));
		if ((ite->first <= l) && (r <= ite->second)) return *ite;
		return { -TINF, -TINF };
	}
	pair<T, T> ByCovered(T  x) { return ByCovered(x, x); }
	// insert
	T Insert(T l, T r) {
		T sumErase = T(0);
		auto ite = prev(st.lower_bound({ l + 1,l + 1 }));
		// no need merge
		if (IsCovered(l, r))return sumErase;
		// first merge pos
		if ((ite->first <= l) && (l <= (ite->second + 1))) {
			l = ite->first;
			sumErase += ite->second - ite->first + 1;
			ite = st.erase(ite);
		}
		else ite = next(ite);
		// merge
		while (r > ite->second) {
			sumErase += ite->second - ite->first + 1;
			ite = st.erase(ite);
		}
		if (((ite->first - 1) <= r) && (r <= ite->second)) {
			r = ite->second;
			sumErase += ite->second - ite->first + 1;
			st.erase(ite);
		}
		st.insert({ l,r });
		return (r - l + 1) - sumErase;
	}
	T Insert(T x) { return Insert(x, x); }
	// erase
	T Erase(T l, T r) {
		//todo
	}
	T Erase(T x) { return Erase(x, x); }
	// range count
	int size() { return st.size() - 2; }
	// mex
	T mex(T x = 0) {
		if (!IsCovered(x)) return x;
		auto ite = prev(st.lowerbound({ x + 1, x + 1 }));
		return ite->second + 1;
	}
	// debug
	void Debug() {
		for (auto[l, r] : st)cout << l << " " << r << endl;
	}
};
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	long long d; cin >> d;
	int q; cin >> q;
	RangeSet<long long>rs(LINF);
	long long ans = 0;
	while (q--) {
		long long l, r; cin >> l >> r;
		rs.Insert(l, r);
		auto [s,e] = rs.ByCovered(l, r);
		chmax(ans, e - s + 1);
		cout << ans << endl;
	}
	return 0;
}