#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

typedef long long ll;

#define sz size()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) (c).begin(), (c).end()
#define rep(i,a,b) for(ll i=(a);i<(b);++i)
#define per(i,a,b) for(ll i=(b-1);i>=(a);--i)
#define clr(a, b) memset((a), (b) ,sizeof(a))
#define ctos(c) string(1,c)
#define print(x) cout<<#x<<" = "<<x<<endl;

#define INF 1000000000000000100LL

int main() {
	ll d,q;
	cin>>d>>q;
	set<pair<ll,ll> > se;
	se.insert(mp(-INF,-INF));
	se.insert(mp(INF,INF));
	ll mx = 0;
	rep(i,0,q){
		ll a,b;
		cin>>a>>b;
		se.insert(mp(a,b));
		set<pair<ll,ll> >::iterator p = --se.lower_bound(mp(a,0));
		if(a-1 <= p->second) a = p->first;
		else p++;
		while(b+1>=p->first){
			b = max(b,p->second);
			set<pair<ll,ll> >::iterator temp = p;
			temp++;
			se.erase(p);
			p = temp;
		}
		se.insert(mp(a,b));
		mx = max(mx,b-a+1);
		cout << mx << endl;
	}
	return 0;
}