#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define R cin>>
#define Z class
#define ll long long
#define ln cout<<'\n'
#define in(a) insert(a)
#define pb(a) push_back(a)
#define pd(a) printf("%.10f\n",a)
#define mem(a) memset(a,0,sizeof(a))
#define all(c) (c).begin(),(c).end()
#define iter(c) __typeof((c).begin())
#define rrep(i,n) for(ll i=(ll)(n)-1;i>=0;i--)
#define REP(i,m,n) for(ll i=(ll)(m);i<(ll)(n);i++)
#define rep(i,n) REP(i,0,n)
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
template<Z A>void pr(A a){cout<<a;ln;}
template<Z A,Z B>void pr(A a,B b){cout<<a<<' ';pr(b);}
template<Z A,Z B,Z C>void pr(A a,B b,C c){cout<<a<<' ';pr(b,c);}
template<Z A,Z B,Z C,Z D>void pr(A a,B b,C c,D d){cout<<a<<' ';pr(b,c,d);}
template<Z A>void PR(A a,ll n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
ll check(ll n,ll m,ll x,ll y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1e9+7,MAXL=1LL<<61,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<ll,ll> P;

void Main() {
  ll n,T;
  cin >> n >> T;
  set<P> s;
  s.in(P(-1,-1));
  ll M=0;
  while(T--) {
    ll x,y;
    cin >> x >> y;
    y++;
    iter(s) it=s.lower_bound(P(x,-1));
    it--;
    ll Mi=x,Ma=y;
    if(it->F<=x&&x<=it->S) {
      Mi=min(Mi,it->F);
      s.erase(it);
    }
    it=s.lower_bound(P(x,-1));
    while(it!=s.end()&&it->F<=y) {
      Ma=max(Ma,it->S);
      s.erase(it);
      it=s.lower_bound(P(x,-1));
    }
    M=max(M,Ma-Mi);
    pr(M);
    s.in(P(Mi,Ma));
  }
}

int main(){ios::sync_with_stdio(0);cin.tie(0);Main();return 0;}