#line 1 "test/yukicoder-674.test.cpp"
#define PROBLEM "https://yukicoder.me/problems/no/674"
#line 2 "stl-expansion.hpp"
#include <bits/stdc++.h>

template <typename T1, typename T2>
std::istream& operator>>(std::istream& is, std::pair<T1, T2>& p) {
    is >> p.first >> p.second;
    return is;
}
template <typename T, size_t N>
std::istream& operator>>(std::istream& is, std::array<T, N>& a) {
    for (size_t i = 0; i < N; ++i) {
        is >> a[i];
    }
    return is;
}
template <typename T>
std::istream& operator>>(std::istream& is, std::vector<T>& v) {
    for (auto& e : v) is >> e;
    return is;
}
template <typename T1, typename T2>
std::ostream& operator<<(std::ostream& os, const std::pair<T1, T2>& p) {
    os << p.first << " " << p.second;
    return os;
}
template <typename T, size_t N>
std::ostream& operator<<(std::ostream& os, const std::array<T, N>& a) {
    for (size_t i = 0; i < N; ++i) {
        os << a[i] << (i + 1 == a.size() ? "" : " ");
    }
    return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os, const std::vector<T>& v) {
    for (size_t i = 0; i < v.size(); ++i) {
        os << v[i] << (i + 1 == v.size() ? "" : " ");
    }
    return os;
}
#line 3 "base.hpp"
using namespace std;

#define REP(i, n) for(int i = 0; i < (int)(n); i++)
#define FOR(i, a, b) for(ll i = a; i < (ll)(b); i++)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define END(...) { print(__VA_ARGS__); return; }

using VI = vector<int>;
using VVI = vector<VI>;
using VVVI = vector<VVI>;
using ll = long long;
using VL = vector<ll>;
using VVL = vector<VL>;
using VVVL = vector<VVL>;
using ull = unsigned long long;
using VUL = vector<ull>;
using VVUL = vector<VUL>;
using VVVUL = vector<VVUL>;
using VD = vector<double>;
using VVD = vector<VD>;
using VVVD = vector<VVD>;
using VS = vector<string>;
using VVS = vector<VS>;
using VVVS = vector<VVS>;
using VC = vector<char>;
using VVC = vector<VC>;
using VVVC = vector<VVC>;
using P = pair<int, int>;
using VP = vector<P>;
using VVP = vector<VP>;
using VVVP = vector<VVP>;
using LP = pair<ll, ll>;
using VLP = vector<LP>;
using VVLP = vector<VLP>;
using VVVLP = vector<VVLP>;

template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using GPQ = priority_queue<T, vector<T>, greater<T>>;

constexpr int INF = 1001001001;
constexpr ll LINF = 1001001001001001001ll;
constexpr int DX[] = {1, 0, -1, 0};
constexpr int DY[] = {0, 1, 0, -1};

void print() { cout << '\n'; }
template<typename T>
void print(const T &t) { cout << t << '\n'; }
template<typename Head, typename... Tail>
void print(const Head &head, const Tail &... tail) {
    cout << head << ' ';
    print(tail...);
}

#ifdef DEBUG
void dbg() { cerr << '\n'; }
template<typename T>
void dbg(const T &t) { cerr << t << '\n'; }
template<typename Head, typename... Tail>
void dbg(const Head &head, const Tail &... tail) {
    cerr << head << ' ';
    dbg(tail...);
}
#else
template<typename... Args>
void dbg(const Args &... args) {}
#endif

template<typename T>
vector<vector<T>> split(typename vector<T>::const_iterator begin, typename vector<T>::const_iterator end, T val) {
    vector<vector<T>> res;
    vector<T> cur;
    for(auto it = begin; it != end; it++) {
        if(*it == val) {
            res.push_back(cur);
            cur.clear();
        } else cur.push_back(*it);
    }
    res.push_back(cur);
    return res;
}

vector<string> split(typename string::const_iterator begin, typename string::const_iterator end, char val) {
    vector<string> res;
    string cur = "";
    for(auto it = begin; it != end; it++) {
        if(*it == val) {
            res.push_back(cur);
            cur.clear();
        } else cur.push_back(*it);
    }
    res.push_back(cur);
    return res;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template <typename T>
pair<VI, vector<T>> compress(const vector<T> &a) {
    int n = a.size();
    vector<T> x;
    REP(i, n) x.push_back(a[i]);
    sort(ALL(x)); x.erase(unique(ALL(x)), x.end());
    VI res(n);
    REP(i, n) res[i] = lower_bound(ALL(x), a[i]) - x.begin();
    return make_pair(res, x);
}

template <typename It>
auto rle(It begin, It end) {
    vector<pair<typename It::value_type, int>> res;
    if(begin == end) return res;
    auto pre = *begin;
    int num = 1;
    for(auto it = begin + 1; it != end; it++) {
        if(pre != *it) {
            res.emplace_back(pre, num);
            pre = *it;
            num = 1;
        } else num++;
    }
    res.emplace_back(pre, num);
    return res;
}

template <typename It>
vector<pair<typename It::value_type, int>> rle_sort(It begin, It end) {
    vector<typename It::value_type> cloned(begin, end);
    sort(ALL(cloned));
    auto e = rle(ALL(cloned));
    sort(ALL(e), [](const auto& l, const auto& r) { return l.second < r.second; });
    return e;
}

template <typename T>
pair<vector<T>, vector<T>> factorial(int n) {
    vector<T> res(n+1), rev(n+1);
    res[0] = 1;
    REP(i, n) res[i+1] = res[i] * (i+1);
    rev[n] = 1 / res[n];
    for(int i = n; i > 0; i--) {
        rev[i-1] = rev[i] * i;
    }
    return make_pair(res, rev);
}
#line 3 "segtree/segment-set.hpp"

template <typename T, T neighbor=1>
struct SegmentSet {
    map<T, T> segments;
    using It = typename map<T, T>::iterator;

    It get(T x) const {
        auto it = segments.upper_bound(x);
        if (it == segments.begin()) return segments.end();
        return prev(it);
    }

    bool contains(T x) const {
        return get(x) != segments.end();
    }

    It insert(T l, T r) {
        auto it = segments.upper_bound(l);
        if(it != segments.begin() && prev(it)->second + neighbor >= l) {
            it = prev(it);
            l = it->first;
        }
        while(it != segments.end() && it->first <= r + neighbor) {
            r = max(r, it->second);
            it = segments.erase(it);
        }
        return segments.emplace_hint(it, l, r);
    }

    void erase(T l, T r) {
        auto it = segments.upper_bound(l);
        if(it != segments.begin() && prev(it)->second + neighbor > l) {
            it = prev(it);
        }
        while(it != segments.end() && it->first < r + neighbor) {
            T nl = it->first, nr = it->second;
            if(nl + neighbor < l) {
                segments.emplace(nl, l - neighbor);
            }
            if(r + neighbor < nr) {
                segments.emplace(r + neighbor, nr);
            }
            it = segments.erase(it);
        }
    }
};
#line 3 "test/yukicoder-674.test.cpp"

int main() {
    ll d; int q; cin >> d >> q;
    SegmentSet<ll> seg;
    ll ans = 0;
    while(q--) {
        ll a, b; cin >> a >> b;
        auto it = seg.insert(a, b);
        chmax(ans, it->second - it->first + 1);
        print(ans);
    }
}