#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    ll d;
    int q;

    cin >> d >> q;

    map<ll, ll> mp;
    ll l = 0;

    for (int i = 0; i < q; i++) {
        ll a, b;
        cin >> a >> b;
        b++;

        auto p = mp.lower_bound(a);
        if (p == mp.end() || b < p->second) {
            mp.insert(make_pair(b, a));
            l = max(l, b - a);
        } else {
            auto t = make_pair(b, a);
            while (1) {
                t = make_pair(max(t.first, p->first), min(t.second, p->second));
                auto g = p++;
                mp.erase(g);
                if (p == mp.end()) break;
                if (t.first < p->second) break;
            }
            mp.insert(t);
            l = max(l, t.first - t.second);
        }

        cout << l << '\n';
    }

    return 0;
}