#include<bits/stdc++.h>
using namespace std;
#define ALL(x) begin(x),end(x)
#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},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 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;
}
template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}


// 閉区間の範囲を管理
template<typename T>
struct RangeSet{
    set<pair<T,T>> st;
    T TINF;

    RangeSet(){
        TINF=numeric_limits<T>::max()/2;
        st.emplace(TINF,TINF);
        st.emplace(-TINF,-TINF);
    }
    // [l,r] covered?
    bool contains(T l,T r){
        assert(l<=r);
        auto ite=prev(st.lower_bound({l+1,l+1}));
        return ite->first<=l and r<=ite->second;
    }
    bool contains(T x){
        return contains(x,x);
    }
    // covered by
    // [l, r]がカバーされているなら，その区間を返す
    // されていないなら-TINFを返す
    pair<T,T> covered_by(T l,T r){
        auto ite=prev(st.lower_bound({l+1,l+1}));
        if(ite->first<=l and r<=ite->second) return *ite;
        return make_pair(-TINF,-TINF);
    }
    // [x, x]がカバーされているなら，その区間を返す
    pair<T,T> covered_by(T x){
        return covered_by(x,x);
    }
    // insert[l,r], 増加量を返す
    T insert(T l,T r){
        auto ite=prev(st.lower_bound({l+1,l+1}));
        if(ite->first<=l and r<=ite->second) return T(0);
        T sum_erased=T(0);
        if(ite->first<=l and l<=ite->second+1){
            l=ite->first;
            sum_erased+=ite->second-ite->first+1;
            ite=st.erase(ite);
        }else ite=next(ite);
        while(r>ite->second){
            sum_erased+=ite->second-ite->first+1;
            ite=st.erase(ite);
        }
        if(ite->first-1<=r and r<=ite->second){
            sum_erased+=ite->second-ite->first+1;
            r=ite->second;
            st.erase(ite);
        }
        st.emplace(l,r);
        return r-l+1-sum_erased;
    }
    T insert(T x){
        return insert(x,x);
    }
    // erase [l,r], 減少量を返す
    T erase(T l,T r){
        assert(l<=r);
        auto ite=prev(st.lower_bound({l+1,l+1}));
        if(ite->first<=l and r<=ite->second){
            // 完全に1つの区間に包含されている
            if(ite->first<l)  st.emplace(ite->first,l-1);
            if(r<ite->second) st.emplace(r+1,ite->second);
            st.erase(ite);
            return r-l+1;
        }

        T ret=T(0);
        if(ite->first<=l and l<=ite->second){
            ret+=ite->second-l+1;// 消えた
            if(ite->first<l) st.emplace(ite->first,l-1);
            ite=st.erase(ite);// 次へ
        }else ite=next(ite);
        while(ite->second<=r){
            ret+=ite->second-ite->first+1;
            ite=st.erase(ite);
        }
        // 右端が区間の間にあるか
        if(ite->first<=r and r<=ite->second){
            ret+=r-ite->first+1;
            if(r<ite->second) st.emplace(r+1,ite->second);
            st.erase(ite);
        }
        return ret;
    }
    T erase(T x){
        return erase(x,x);
    }
    // number of range
    int size(){
        return (int)st.size()-2;
    }
    // mex [x,~)
    int mex(T x=0){
        auto ite=prev(st.lower_bound({x+1,x+1}));
        if(ite->first<=x and x<=ite->second) return ite->second+1;
        else return x;
    }
    void output(){
        cout<<"RangeSet : ";
        for(auto &p:st){
            if(p.first==-TINF or p.second==TINF) continue;
            cout<<"["<<p.first<<", "<<p.second<<"] ";
        }
        cout<<"\n";
    }
};


signed main(){
    ll d,q;cin>>d>>q;
    RangeSet<ll> st;
    ll res=0;
    while(q--){
        ll l,r;cin>>l>>r;
        st.insert(l,r);
        auto p=st.covered_by(l);
        chmax(res,p.second-p.first+1);
        cout<<res<<"\n";
    }
    return 0;
}