#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,fma,popcnt,bmi,bmi2")
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef int64_t lint;
#define rep(i, n) for(lint i=0; i<n; i++)
#define repx(i, l, n) for(lint i=l; i<n; i++)
#define all(v) v.begin(), v.end()
#define show(x) cout << #x << ": " << x << endl;
#define list(x) cout << #x << ": " << x << "  ";
#define pb push_back
using vi = vector<lint>;
using vvi = vector<vector<lint>>;
template<class T> inline void vin(vector<T>& v) { rep(i, v.size()) cin >> v.at(i); }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T> inline void drop(T x) { cout << x << endl; exit(0); }
template<class T> void vout(vector<T> v) { rep(i, v.size()) { cout << v.at(i) << ' '; } cout << endl; }
constexpr lint LINF = LLONG_MAX/2;

class SegmentMap : public map<lint, lint> {
private:
	bool flagToMergeAdjacentSegment;
public:
	// if merge [l, c] and [c+1, r], set flagToMergeAdjacentSegment to true
	SegmentMap(bool flagToMergeAdjacentSegment) :
		flagToMergeAdjacentSegment(flagToMergeAdjacentSegment) {}
	// __exist -> iterator pair(l, r) (contain p)
	// noexist -> map.end()
	auto get(lint p) const {
		auto it = upper_bound(p);
		if (it == begin() || (--it)->second < p) return end();
		return it;
	}
	// insert segment [l, r]
	void insert(lint l, lint r) {
		auto itl = upper_bound(l), itr = upper_bound(r + flagToMergeAdjacentSegment);
		if (itl != begin()) {
			if ((--itl)->second < l - flagToMergeAdjacentSegment) ++itl;
		}
		if (itl != itr) {
			l = min(l, itl->first);
			r = max(r, prev(itr)->second);
			erase(itl, itr);
		}
		(*this)[l] = r;
	}
	// remove segment [l, r]
	void remove(lint l, lint r) {
		auto itl = upper_bound(l), itr = upper_bound(r);
		if (itl != begin()) {
			if ((--itl)->second < l) ++itl;
		}
		if (itl == itr) return;
		int tl = min(l, itl->first), tr = max(r, prev(itr)->second);
		erase(itl, itr);
		if (tl < l) (*this)[tl] = l - 1;
		if (r < tr) (*this)[r + 1] = tr;
	}
	// Is p and q in same segment?
	bool same(lint p, lint q) const {
		const auto&& it = get(p);
		return it != end() && it->first <= q && q <= it->second;
	}
};

int main() {
	lint D, Q;
	cin >> D >> Q;

	lint a=0, b=0, c=0, x, y, z;
	SegmentMap m(true);
	rep(i, Q) {
		cin >> x >> y;
		m.insert(x, y);
		auto t = m.get(x);
		chmax(a, t->second-t->first+1);
		cout << a << endl;
	}
}