#include <bits/stdc++.h>

#if __has_include(<atcoder/all>)
#include <atcoder/all>
std::istream &operator>>(std::istream &is, atcoder::modint &v) {
    long long value;
    is >> value;
    v = value;
    return is;
}
std::ostream &operator<<(std::ostream &os, const atcoder::modint &v) {
    os << v.val();
    return os;
}
std::ostream &operator<<(std::ostream &os, const atcoder::modint998244353 &v) {
    os << v.val();
    return os;
}
std::istream &operator>>(std::istream &is, atcoder::modint998244353 &v) {
    long long x;
    is >> x;
    v = x;
    return is;
}
std::ostream &operator<<(std::ostream &os, const atcoder::modint1000000007 &v) {
    os << v.val();
    return os;
}
std::istream &operator>>(std::istream &is, atcoder::modint1000000007 &v) {
    long long x;
    is >> x;
    v = x;
    return is;
}
#endif

using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define newl '\n';
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define rrep(i, s, t) for (ll i = (ll)(t) - 1; i >= (ll)(s); i--)
#define all(x) begin(x), end(x)
#define eb emplace_back
#define pb push_back
#define TT template <typename T>
TT using vec = vector<T>;
TT using vvec = vec<vec<T>>;
TT using vvvec = vec<vvec<T>>;
TT using minheap = priority_queue<T, vector<T>, greater<T>>;
TT using maxheap = priority_queue<T>;
TT bool chmin(T &x, T y) { return x > y ? (x = y, true) : false; }
TT bool chmax(T &x, T y) { return x < y ? (x = y, true) : false; }
TT bool rng(T l, T x, T r) { return l <= x && x < r; }
TT T flr(T a, T b) {
    if (b < 0) a = -a, b = -b;
    return a >= 0 ? a / b : (a + 1) / b - 1;
}

TT T cil(T a, T b) {
    if (b < 0) a = -a, b = -b;
    return a > 0 ? (a - 1) / b + 1 : a / b;
}
TT T sqr(T x) { return x * x; }
struct io_setup {
    io_setup() {
        ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
        cout << fixed << setprecision(15);
    }
} io_setup;

template <class T1, class T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
    os << p.first << " " << p.second;
    return os;
}

TT ostream &operator<<(ostream &os, const vec<T> &v) {
    for (size_t i = 0; i < v.size(); i++) {
        os << v[i] << (i + 1 != v.size() ? " " : "");
    }
    return os;
}

template <typename T, ll n>
ostream &operator<<(ostream &os, const array<T, n> &v) {
    for (size_t i = 0; i < n; i++) {
        os << v[i] << (i + 1 != n ? " " : "");
    }
    return os;
}

template <typename T> ostream &operator<<(ostream &os, const vvec<T> &v) {
    for (size_t i = 0; i < v.size(); i++) {
        os << v[i] << (i + 1 != v.size() ? "\n" : "");
    }
    return os;
}

TT istream &operator>>(istream &is, vec<T> &v) {
    for (size_t i = 0; i < v.size(); i++) {
        is >> v[i];
    }
    return is;
}

#if __has_include(<debug/debug.hpp>)
#include <debug/debug.hpp>
#else
#define dbg(...) true
#define DBG(...) true
#define OUT(...) true
#endif

template <typename T, bool merge_adju> struct rangeset : public std::map<T, T> {
    rangeset() {}
    auto get(T p) const {
        auto it = (*this).upper_bound(p);
        if (it == (*this).begin() || (--it)->second <= p) return (*this).end();
        return it;
    }

    //[l, r)
    void insert(T l, T r) {
        if (l == r) return;
        assert(l <= r);
        auto itl = (*this).upper_bound(l),
             itr = (*this).lower_bound(r + merge_adju);
        if (itl != (*this).begin() && (--itl)->second + merge_adju <= l) {
            ++itl;
        }

        if (itl != itr) {
            if (itl->first < l) l = itl->first;
            if (prev(itr)->second > r) r = prev(itr)->second;
            map<T, T>::erase(itl, itr);
        }
        (*this)[l] = r;
    }

    //[l, r)
    void erase(T l, T r) {
        if (l == r) return;
        assert(l <= r);
        auto itl = (*this).upper_bound(l), itr = (*this).lower_bound(r);
        if (itl != (*this).begin() && (--itl)->second <= l) {
            ++itl;
        }
        if (itl == itr) return;
        T tl = l, tr = r;
        if (itl->first < l) tl = itl->first;
        if (prev(itr)->second > r) tr = prev(itr)->second;
        map<T, T>::erase(itl, itr);
        if (tl < l) (*this)[tl] = l;
        if (tr > r) (*this)[r] = tr;
    }

    bool contains(T p) const { return get(p) != (*this).end(); }
    bool same(T a, T b) const {
        if (a > b) swap(a, b);

        auto it = get(a);
        if (it == (*this).end()) return false;
        return b < it->second;
    }

    T mex(T x = 0) const {
        auto it = get(x);
        if(it == (*this).end()) return x;
        else return it -> second;
    }

    template <typename TYPE, bool ME>
    friend ostream &operator<<(ostream &os, rangeset<TYPE, ME> const &rhs) {
        for (auto [l, r] : rhs) os << "[" << l << ", " << r << ")";
        return os;
    }
};

int main() {
    ll d, q;
    cin >> d >> q;
    rangeset<ll, true> rs;

    ll ans = 0;

    while(q--) {
        ll a, b;
        cin >> a >> b;
        b++;
        rs.insert(a, b);
        auto it = rs.get(a);
        chmax(ans, it -> second - it -> first);
        cout << ans << newl;
    }
    
}