#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T> V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T> mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }

/*
 <url:>
 問題文============================================================
 =================================================================
 解説=============================================================
 ================================================================
 */

void solve(){
    ll D,Q; cin >> D >> Q;
    vector<ll> A(Q),B(Q);
    for(int i = 0; i < Q;i++) cin >> A[i] >> B[i];
    queue<pll> q;
    for(int i = 0; i < Q;i++){
        int qs = (int)q.size();
        pll ap = {A[i],B[i]};
        
        bool f = false;
        for(int j = 0; j < qs; j++){
            auto p = q.front(); q.pop();
            if(f){ q.push(p); continue;}
            
            if(p.second+1 < ap.first){
                q.push(p);
                continue;
            }
            if(p.first-1 > ap.second){
                q.push(ap);
                q.push(p);
                f = true;
                continue;
            }
            
            ap.first = min(p.first,ap.first);
            ap.second = max(p.second,ap.second);
        }
        if(!f) q.push(ap);
        
        ll ans = -1;
        qs = int(q.size());
        while(qs--){
            auto p = q.front(); q.pop();
            ans = max(ans,p.second - p.first + 1);
            q.push(p);
        }
        cout << ans << endl;
    }
}
int main(void) {
    cin.tie(0); ios_base::sync_with_stdio(false);
    solve();
    return 0;
}