#include <bits/stdc++.h>
#define GET_REP(_1, _2, _3, NAME, ...) NAME
#define rep(...) GET_REP(__VA_ARGS__, irep, _rep)(__VA_ARGS__)
#define rep1(...) GET_REP(__VA_ARGS__, irep1, _rep1)(__VA_ARGS__)
#define _rep(i, n) irep (i, 0, n)
#define _rep1(i, n) irep1(i, 1, n)
#define irep(i, a, n) for (int i = a; i < (int)(n); ++i)
#define irep1(i, a, n) for (int i = a; i <= (int)(n); ++i)
#define rrep(i, n) for (int i = (int)(n) - 1; i >= 0; --i)
#define rrep1(i, n) for (int i = (int)(n); i >= 1; --i)
#define allrep(X, x) for (auto &&X : x)
#define all(x) begin(x), end(x)
#define debug(x) cout << #x " => " << (x) << endl
#ifdef LOCAL
  #include "../../Lib/cout_container.hpp"
#endif
using lint = long long;
constexpr int MOD = (int)1e9 + 7;
constexpr double EPS = 1e-9;
using namespace std;
namespace { struct INIT { INIT() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } INIT; }

template <bool merge_adjacent>
class SectionUnion {
  public:
  map<long long, long long> sec;
  SectionUnion(void) {}
  pair<bool, pair<long long, long long>> get(const long long x) const {
    auto itr = sec.lower_bound(x);
    return {!(itr == sec.end() && x < itr->second), {itr->second, itr->first}};
  }
  bool insert(long long l, long long r) {
    auto litr = sec.lower_bound(l - merge_adjacent), ritr = sec.lower_bound(r);
    if (ritr != sec.end() && r + merge_adjacent >= ritr->second) ++ritr;
    const bool exist = litr != ritr;
    if (exist) {
      l = min(l, litr->second), r = max(r, prev(ritr)->first);
      sec.erase(litr, ritr);
    }
    sec.emplace(r, l);
    return exist;
  }
  bool remove(long long l, long long r, bool involve = false) {
    auto litr = sec.lower_bound(l), ritr = sec.lower_bound(r);
    if (ritr != sec.end() && r >= ritr->second) ++ritr;
    const bool exist = litr != ritr;
    if (exist) {
      long long ledge = litr->second, redge = prev(ritr)->first;
      sec.erase(litr, ritr);
      if (!involve) {
        if (ledge < l) sec[l - 1] = ledge;
        if (r < redge) sec[redge] = r + 1;
      }
    }
    return exist;
  }
  bool same(long long a, long long b) const {
    if (b < a) swap(a, b);
    auto itr = sec.lower_bound(b);
    return itr != sec.end() && itr->second <= a;
  }
  void clear(void) { sec.clear(); }
  bool empty(void) const { return sec.empty(); }
  int  size(void) const { return sec.size(); }
};

int main(void) {
  lint d, q;
  cin >> d >> q;
  vector<pair<lint, lint>> ab(q);
  rep (i, q) cin >> ab[i].first >> ab[i].second;
  SectionUnion<true> su;
  lint maxi = 0;
  vector<lint> ans(q + 1);
  rep (i, q) {
    su.insert(ab[i].first, ab[i].second);
    auto p = su.get(ab[i].first).second;
    ans[i + 1] = max(ans[i], p.second - p.first + 1);
  }
  rep1 (i, q) cout << ans[i] << endl;
  return 0;
}