#include<bits/stdc++.h>
#define rep(i,j,n) for(ll i=j;i<(ll)(n);i++)
#define rrep(i,j,n)  for(ll i=j;i>=n;i--)
#define all(x) (x).begin(),(x).end()
#define m0(x) memset(x,0,sizeof(x))
#define pb push_back
#define mp make_pair
#define perm(c) sort(all(c)); for(bool c##p=1;c##p;c##p=next_permutation(all(c)))
#define UNIQUE(v) sort(v.begin(),v.end()); v.erase(unique(v.begin(),v.end()),v.end())

using namespace std;
typedef long long ll;
typedef long double ld;
template<class T> bool chmax(T &a, const T &b){if(a<b) {a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b){if(a>b) {a=b;return 1;}return 0;}

ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll max(ll a,ll b){return a>b?a:b;}
ll min(ll a,ll b){return a<b?a:b;}

struct interval_set{
    interval_set(){
        st.insert(mp(-(1LL << 60),-(1LL << 60)));
        st.insert(mp(1LL << 60,1LL << 60));
    }
    void insert(ll l,ll r){
        st.insert(mp(l,r));
        auto iter = st.find(make_pair(l,r));
        vector<pair<ll,ll>> erase_vec;

        ll left = l,right = r;
        for(auto iter_ = iter;;iter_++){
            if(right < iter_->first) break;
            erase_vec.push_back(*iter_);
            right = max(right,iter_->second);
        }
        for(auto iter_ = iter;;iter_--){
            if(iter_->second < left) break;
            erase_vec.push_back(*iter_);
            left = min(left,iter_->first);
        }

        for(auto _ : erase_vec){
            auto iter_ = st.find(_);
            if(iter_ != st.end())
                st.erase(iter_);
        }
        st.insert(mp(left,right));
        chmax(max_len,right - left);
    }

    ll max_length(){
        return max_len;
    }

    set<pair<ll,ll>> st;
    ll max_len = 0;
};

void solve(){
    ll d,q; cin >> d >> q;
    vector<ll> a(q),b(q);
    rep(i,0,q) cin >> a[i] >> b[i];
    interval_set is;
    rep(i,0,q){
        is.insert(a[i],b[i]+1);
        cout << is.max_length() << endl;
    }
}

int main(){
    cin.tie(nullptr);
    cout << fixed << setprecision(20);

    ll T;
    T = 1;
    /*
       cin >> T;
       */
    while(T--) solve();
}