#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N=3e4+10;
int d,q,l[N],r[N];
set<int> s;
signed main(){
	//freopen("onduty.in","r",stdin);
	//freopen("onduty.out","w",stdout); 
	cin>>d>>q;
	for(int i=1;i<=q;i++){
		cin>>l[i]>>r[i];
		s.insert(l[i]-1);
		s.insert(l[i]);
		s.insert(r[i]);;
		s.insert(r[i]+1); 
	}
	int ans=0;
	for(int i=1;i<=q;i++){
		while(!s.empty()){
			auto it=s.lower_bound(l[i]);
			if(*it>r[i]) break;
			s.erase(it); 
		}
		auto R=s.lower_bound(l[i]);
		auto L=R;--L;
		ans=max(ans,*R-*L-1);
		cout<<ans<<'\n';
	}
	return 0;
}