#include <bits/stdc++.h>
using namespace std;

int main() {
    constexpr int64_t inf = 2e18;
    int64_t d, q;
    cin >> d >> q;

    map<int64_t, int64_t> mp;
    mp[-inf] = -inf;
    mp[inf] = inf;
    int64_t ans = 0;
    for (int i = 0; i < q; i++) {
        int64_t a, b;
        cin >> a >> b;
        int64_t l = a, r = b;
        auto it = mp.upper_bound(a);
        it--;
        if (it->first < a and it->second >= a - 1) {
            l = it->first;
            it = mp.erase(it);
        } else {
            it++;
        }
        while (it->first <= b + 1) {
            r = max(r, it->second);
            it = mp.erase(it);
        }
        mp[l] = r;
        ans = max(ans, r - l + 1);
        cout << ans << endl;
    }
    return 0;
}