#include "bits/stdc++.h"

using namespace std;

#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define all(c) c.begin(),c.end()
const int inf = 1000000001;
const ll INF = 2e18;
const ll MOD = 1000000007;
//const ll mod = 1000000009;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p;//<<endl;
int dx[4] = { 1,0, -1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };


int main() {
	ll d, q;
	cin >> d >> q;
	map<ll, ll> l2r;
	l2r[-5] = -5;
	ll ans = 0;
	rep(i, q) {
		ll a, b;
		cin >> a >> b;
		while (true) {
			auto itr = l2r.lower_bound(a);
			if (itr == l2r.end()) {
				break;
			}
			else if (itr->first <= b + 1) {
				b = max(b, itr->second);
				l2r.erase(itr);
			}
			else {
				break;
			}
		}
		while (true) {
			auto itr = l2r.lower_bound(a);
			itr--;
			if (itr->second >= a - 1) {
				a = min(a, itr->first);
				l2r.erase(itr);
			}
			else {
				break;
			}
		}
		ans = max(ans, b - a + 1);
		cout << ans << endl;
		l2r[a] = b;
	}
}