#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = uint32_t;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    ll d, q;
    cin >> d >> q;
    using P = pair<ll, ll>;
    set<P> m;
    ll ans = 0;
    for (int i = 0; i < q; ++i) {
        ll a, b;
        scanf("%lld %lld", &a, &b);
        b++;
        auto x = m.upper_bound({a, b});
        if(x != m.begin()) x--;
        while(x != m.end() && x->second < a) x++;
        while(x != m.end() && b >= x->first){
            a = min(a, x->first); b = max(b, x->second);
            x = m.erase(x);
        }
        m.emplace(a, b);
        ans = max(ans, b-a);
        printf("%lld\n", ans);
    }

    return 0;
}