#include "bits/stdc++.h" using namespace std; typedef long long ll; typedef pair pii; typedef pair pll; const int INF = 1e9; const ll LINF = 1e18; template ostream& operator << (ostream& out,const pair& o){ out << "(" << o.first << "," << o.second << ")"; return out; } template ostream& operator << (ostream& out,const vector V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; } template ostream& operator << (ostream& out,const vector > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; } template ostream& operator << (ostream& out,const map 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; } /* 問題文============================================================ ================================================================= 解説============================================================= ================================================================ */ void solve(){ ll D,Q; scanf("%lld%lld",&D,&Q); // cin >> D >> Q; vector A(Q),B(Q); for(int i = 0; i < Q;i++){ scanf("%lld%lld",&A[i],&B[i]); } queue 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); } printf("%lld\n",ans); // cout << ans << endl; } } int main(void) { cin.tie(0); ios_base::sync_with_stdio(false); solve(); return 0; }