#if !__INCLUDE_LEVEL__

#include __FILE__
// 閉区間の範囲を管理
template <typename T>
struct RangeSet {
    set<pair<T, T>> st;
    T TINF;

    RangeSet() {
        TINF = numeric_limits<T>::max() / 2;
        st.emplace(TINF, TINF);
        st.emplace(-TINF, -TINF);
    }
    // [l,r] covered?
    bool covered(T l, T r) {
        assert(l <= r);
        auto ite = prev(st.lower_bound({l + 1, l + 1}));
        return ite->first <= l and r <= ite->second;
    }
    bool covered(T x) { return covered(x, x); }
    // [l, r]がカバーされているなら，その区間を返す.
    // されていないなら[-TINF,-TINF]を返す
    pair<T, T> covered_by(T l, T r) {
        assert(l <= r);
        auto ite = prev(st.lower_bound({l + 1, l + 1}));
        if (ite->first <= l and r <= ite->second) return *ite;
        return make_pair(-TINF, -TINF);
    }
    pair<T, T> covered_by(T x) { return covered_by(x, x); }
    // insert[l,r], 増加量を返す
    T insert(T l, T r) {
        assert(l <= r);
        auto ite = prev(st.lower_bound({l + 1, l + 1}));
        if (ite->first <= l and r <= ite->second) return T(0);
        T sum_erased = T(0);
        if (ite->first <= l and l <= ite->second + 1) {
            l = ite->first;
            sum_erased += ite->second - ite->first + 1;
            ite = st.erase(ite);
        } else
            ite = next(ite);
        while (r > ite->second) {
            sum_erased += ite->second - ite->first + 1;
            ite = st.erase(ite);
        }
        if (ite->first - 1 <= r and r <= ite->second) {
            sum_erased += ite->second - ite->first + 1;
            r = ite->second;
            st.erase(ite);
        }
        st.emplace(l, r);
        return r - l + 1 - sum_erased;
    }
    T insert(T x) { return insert(x, x); }
    // erase [l,r], 減少量を返す
    T erase(T l, T r) {
        assert(l <= r);
        auto ite = prev(st.lower_bound({l + 1, l + 1}));
        if (ite->first <= l and r <= ite->second) {
            // 完全に1つの区間に包含されている
            if (ite->first < l) st.emplace(ite->first, l - 1);
            if (r < ite->second) st.emplace(r + 1, ite->second);
            st.erase(ite);
            return r - l + 1;
        }

        T ret = T(0);
        if (ite->first <= l and l <= ite->second) {
            ret += ite->second - l + 1;  // 消えた
            if (ite->first < l) st.emplace(ite->first, l - 1);
            ite = st.erase(ite);  // 次へ
        } else
            ite = next(ite);
        while (ite->second <= r) {
            ret += ite->second - ite->first + 1;
            ite = st.erase(ite);
        }
        // 右端が区間の間にあるか
        if (ite->first <= r and r <= ite->second) {
            ret += r - ite->first + 1;
            if (r < ite->second) st.emplace(r + 1, ite->second);
            st.erase(ite);
        }
        return ret;
    }
    T erase(T x) { return erase(x, x); }
    // number of range
    int size() { return (int)st.size() - 2; }
    // mex [x,~)
    T mex(T x = 0) {
        auto ite = prev(st.lower_bound({x + 1, x + 1}));
        if (ite->first <= x and x <= ite->second)
            return ite->second + 1;
        else
            return x;
    }
    void output() {
        cout << "RangeSet : ";
        for (auto &p : st) {
            if (p.first == -TINF or p.second == TINF) continue;
            cout << "[" << p.first << ", " << p.second << "] ";
        }
        cout << "\n";
    }
};
int main()
{
    ll D,Q;cin >> D >> Q;
    RangeSet<ll> st;
    ll Ans = 0;
    rep(q,Q){
        ll L,R;cin >> L >> R;
        st.insert(L,R);
        auto ran = st.covered_by(L);
        chmax(Ans,ran.second-ran.first+1);
        cout << Ans << endl;
    }
}

#else

#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rrep(i, n) for(int i = n-1; i >= 0; i--)
#define range(i, m, n) for(int i = m; i < n; i++)
#define fore(i,a) for(auto &i:a)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define Sum(v) accumulate(all(v),0)
#define minv(v) *min_element(all(v))
#define maxv(v) *max_element(all(v))
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
const ll INF = 1e16;
const ll MOD1 = 1000000007;
const ll MOD2 = 998244353;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
ll SN(char s){return ll(s-'0');}
ll SN(string s){return stoll(s);}
int alpN(char s){return int(s-'a');}
int AlpN(char s){return int(s-'A');}
using Graph = vector<vector<ll>>;
using GraphCost = vector<vector<pair<ll,ll>>>;
using mint1 = modint1000000007;
using mint2 = modint998244353;
using pll = pair<long long, long long>;
template <class T>ostream &operator<<(ostream &o,const vector<T>&v){for(int i=0;i<(int)v.size();i++)o<<(i>0?" ":"")<<v[i];return o;}//vector空白区切り出力
ostream& operator<<(ostream& os, const mint1& N) {return os << N.val();}//mint出力。デフォはmint1
ostream& operator<<(ostream& os, const mint2& N) {return os << N.val();}
template<class T> bool contain(const std::string& s, const T& v) {
    return s.find(v) != std::string::npos;
}

#endif