#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define sar(a,n) cout<<#a<<":";rep(pachico,n)cout<<" "<<a[pachico];cout<<endl
#define svec(v) cout<<#v<<":";rep(pachico,v.size())cout<<" "<<v[pachico];cout<<endl
#define svecp(v) cout<<#v<<":";each(pachico,v)cout<<" {"<<pachico.first<<":"<<pachico.second<<"}";cout<<endl
#define sset(s) cout<<#s<<":";each(pachico,s)cout<<" "<<pachico;cout<<endl
#define smap(m) cout<<#m<<":";each(pachico,m)cout<<" {"<<pachico.first<<":"<<pachico.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

const int MAX_N = 100005;

//セグ木で持てないくらい大きい範囲の(0,1)の区間更新のクエリに答える
//この実装では最終的に和を答える
template<typename T> class UpdateSet
{
private:
    using ptt = pair<T,T>;
    T inf;
    multiset<T> mx;
public:
    set<ptt> st;
    UpdateSet() : inf(numeric_limits<T>::max()){
        mx = {0};
    };
    //[l,r)をk(0,1)に更新
    void update(T l,T r,int k){
        T lb = l, rb = r;
        while(1){
            auto it = st.lower_bound(ptt(l,-inf));
            if(it == st.end()){
                break;
            }
            ptt p = *it;
            if(p.fi >= r){
                break;
            }
            st.erase(it);
            mx.erase(mx.find(p.se-p.fi));
            if(p.se > r){
                rb = max(rb,p.se);
                break;
            }
        }
        auto it = st.lower_bound(ptt(l,-inf));
        if(it != st.begin()){
            --it;
            ptt p = *it;
            if(p.se >= l){
                st.erase(it);
                mx.erase(mx.find(p.se-p.fi));
                lb = min(lb,p.fi);
            }
            if(p.se > r){
                rb = max(rb,p.se);
            }
        }
        if(k == 1){
            st.insert(ptt(lb,rb));
            mx.insert(rb-lb);
        }
    }
    T query(){
        return *(--mx.end());
    }
};

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll d;
    int q;
    cin >> d >> q;
    UpdateSet<ll> us;
    rep(i,q){
        ll a,b;
        cin >> a >> b;
        us.update(a,b+1,1);
        cout << us.query() << "\n";
    }
    return 0;
}