#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}
 
struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;
 
template<typename T1,typename T2>
ostream &operator<<(ostream &os,const pair<T1,T2>&p){
    os<<p.first<<" "<<p.second;
    return os;
}
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}

signed main(){
    ll d;int q;cin>>d>>q;

    using P=pair<ll,ll>;
    set<P> st;
    st.insert(P(-LINF,-LINF));
    st.insert(P(LINF,LINF));

    ll ans=0;
    rep(_,q){
        ll a,b;cin>>a>>b;b++;
        auto ite=st.lower_bound(P(a,b));
        ite=prev(ite);
        if((ite->first)<=a and b<=(ite->second)){
            cout<<ans<<endl;
            continue;
        }
        if((ite->second)>=a){
            a=ite->first;
            ite=st.erase(ite);
        }else ite=next(ite);
        while(b>=(ite->second))ite=st.erase(ite);
        if(b<ite->first){
        }
        else{
            b=ite->second;
            st.erase(ite);
        }
        chmax(ans,b-a);
        st.insert(P(a,b));
        cout<<ans<<"\n";
    }

    return 0;
}