#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

int main() {
  ll D, Q;
  cin >> D >> Q;

  vector<ll> A(Q);
  vector<ll> B(Q);
  set<ll> S;

  for (int i = 0; i < Q; ++i) {
    cin >> A[i] >> B[i];

    S.insert(A[i] - 1);
    S.insert(A[i]);
    S.insert(B[i]);
    S.insert(B[i] + 1);
  }

  ll ans = 0;

  for (int i = 0; i < Q; ++i) {
    ll a = A[i];
    ll b = B[i];

    while (true) {
      auto it = S.lower_bound(a);
      if (*it > b) break;

      S.erase(*it);
    }

    auto it = S.lower_bound(a);
    ll end_at = *it;
    --it;
    ll start_at = *it;

    // fprintf(stderr, "(%lld, %lld)\n", start_at, end_at);
    ans = max(ans, end_at - start_at - 1);
    cout << ans << endl;
  }

  return 0;
}