#include <bits/stdc++.h>
#define REP(i, n) for(int i = 0;i < n;i++)
#define ll long long
using namespace std;
typedef pair<int, int> P;
typedef pair<ll,ll> LP;
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const int INF = 1000000000;
const ll LINF = 1000000000000000000;//1e18
const double PI = acos(-1.0);
const double EPS = 1e-10;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
inline constexpr ll ceil_div(const ll a, const ll b) {return (a + b - 1) / b - !!((a + b - 1) % b < 0);}// return ceil(a/b)
inline constexpr ll floor_div(const ll a, const ll b) {return a / b - !!(a % b < 0);}// return floor(a/b)

/*  ----------------------- DEBUG FUNCTION ---------------------------- */
#define DUMPOUT cerr
void dump_function() { DUMPOUT << ' '; }
void dump_function(bool a) { DUMPOUT << a; }
void dump_function(int a) { DUMPOUT << a; }
void dump_function(long long a) { DUMPOUT << a; }
void dump_function(char a) { DUMPOUT << a; }
void dump_function(string &a) { DUMPOUT << a; }
void dump_function(double a) { DUMPOUT << a; }
template <class T> void dump_function(const vector<T> &);
template <class T, size_t size> void dump_function(const array<T, size> &);
template <class T, class L> void dump_function(const pair<T, L> &p);
template <class T, size_t size> void dump_function(const T (&)[size]);
template <class T> void dump_function(const vector<T> &a) {
    if(a.empty()) return;
    dump_function(a[0]);
    for(auto i = a.begin(); ++i != a.end();) {
        DUMPOUT << " ";
        dump_function(*i);
    }
    DUMPOUT << endl;
}
template <class T> void dump_function(const deque<T> &a) {
    if(a.empty()) return;
    dump_function(a[0]);
    for(auto i = a.begin(); ++i != a.end();) {
        DUMPOUT << " ";
        dump_function(*i);
    }
}
template <class T, size_t size> void dump_function(const array<T, size> &a) {
    dump_function(a[0]);
    for(auto i = a.begin(); ++i != a.end();) {
        DUMPOUT << " ";
        dump_function(*i);
    }
}
template <class T, class L> void dump_function(const pair<T, L> &p) {
    DUMPOUT << '(';
    dump_function(p.first);
    DUMPOUT << ",";
    dump_function(p.second);
    DUMPOUT << ')';
}
template <class T> void dump_function(set<T> &x) {
    for(auto e : x) dump_function(e), DUMPOUT << " ";
    DUMPOUT << endl;
}
template <class T> void dump_function(multiset<T> &x) {
    for(auto e : x) dump_function(e), DUMPOUT << " ";
    DUMPOUT << endl;
}
template <class T, size_t size> void dump_function(const T (&a)[size]) {
    dump_function(a[0]);
    for(auto i = a; ++i != end(a);) {
        DUMPOUT << " ";
        dump_function(*i);
    }
}
template <class T> void dump_function(const T &a) { DUMPOUT << a; }
int dump_out() {
    DUMPOUT << '\n';
    return 0;
}
template <class T> int dump_out(const T &t) {
    dump_function(t);
    DUMPOUT << '\n';
    return 0;
}
template <class Head, class... Tail> int dump_out(const Head &head, const Tail &... tail) {
    dump_function(head);
    DUMPOUT << ' ';
    dump_out(tail...);
    return 0;
}

#ifdef DEBUG_
#define dump(x)                                                                                                                                               \
    DUMPOUT << #x << ": ";                                                                                                                                        \
    dump_function(x);                                                                                                                                                  \
    DUMPOUT << endl;
void dumps() {}
template <class T> void dumps(const T &t) {
    dump_function(t);
    DUMPOUT << " ";
}
template <class Head, class... Tail> void dumps(const Head &head, const Tail &... tail) {
    dump_function(head);
    DUMPOUT << ' ';
    dump_out(tail...);
}
#else
#define dump(x)
template <class... T> void dumps(const T &...) {}
#endif
/*  ----------------------- DEBUG FUNCTION ---------------------------- */

template<int MOD> struct Fp {
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
        if (val < 0) val += MOD;
    }
    constexpr int getmod() const { return MOD; }
    constexpr Fp operator - () const noexcept {
        return val ? MOD - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MOD) val -= MOD;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MOD;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b, swap(a, b);
            u -= t * v, swap(u, v);
        }
        val = val * u % MOD;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
    friend constexpr istream& operator >> (istream& is, Fp<MOD>& x) noexcept {
        is >> x.val;
        x.val %= MOD;
        if (x.val < 0) x.val += MOD;
        return is;
    }
    friend constexpr ostream& operator << (ostream& os, const Fp<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD>& r, long long n) noexcept {
        if (n == 0) return 1;
        auto t = modpow(r, n / 2);
        t = t * t;
        if (n & 1) t = t * r;
        return t;
    }
    friend constexpr Fp<MOD> modinv(const Fp<MOD>& r) noexcept {
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b, swap(a, b);
            u -= t * v, swap(u, v);
        }
        return Fp<MOD>(u);
    }
};


template<class T> struct BiCoef {
    vector<T> fact_, inv_, finv_;
    constexpr BiCoef() {}
    constexpr BiCoef(int n) noexcept : fact_(n, 1), inv_(n, 1), finv_(n, 1) {
        init(n);
    }
    constexpr void init(int n) noexcept {
        fact_.assign(n, 1), inv_.assign(n, 1), finv_.assign(n, 1);
        int MOD = fact_[0].getmod();
        for(int i = 2; i < n; i++){
            fact_[i] = fact_[i-1] * i;
            inv_[i] = -inv_[MOD%i] * (MOD/i);
            finv_[i] = finv_[i-1] * inv_[i];
        }
    }
    constexpr T com(int n, int k) const noexcept {
        if (n < k || n < 0 || k < 0) return 0;
        return fact_[n] * finv_[k] * finv_[n-k];
    }
    constexpr T fact(int n) const noexcept {
        if (n < 0) return 0;
        return fact_[n];
    }
    constexpr T inv(int n) const noexcept {
        if (n < 0) return 0;
        return inv_[n];
    }
    constexpr T finv(int n) const noexcept {
        if (n < 0) return 0;
        return finv_[n];
    }
    constexpr T perm(int n, int k) const noexcept {
        if (n < k || n < 0 || k < 0) return 0;
        return fact_[n] * finv_[n-k];
    }
};

/* ----------------------------- MOD ----------------------------------- */
const int MOD = 1000000007;
const int MOD2 = 998244353;
using mint = Fp<MOD>;
BiCoef<mint> bc;
// using vec = vector<int>;
// using mat = vector<vec>;
/* ----------------------------- MOD ----------------------------------- */

/*  ----------------------- AtCoder Library ---------------------------- */
// #include <atcoder/all>
// using namespace atcoder;
/*  ----------------------- AtCoder Library ---------------------------- */

template<class T>
struct RangeSet {
private:
	const T TINF = numeric_limits<T>::max() / 2;
	set<pair<T, T>> st;

public:
	RangeSet() {
		st.emplace(-TINF, -TINF + 1);
		st.emplace(TINF, TINF + 1);
	}

	//[l, r) が含まれるかどうか
	bool covered(T l, T r) {
		assert(l < r);
		auto itr = prev(st.lower_bound({l + 1, -TINF}));
		return itr->first <= l and r <= itr->second;
	}

	//[l, l + 1) が含まれるかどうか
	bool covered(T l) { return covered(l, l + 1); }

    // [l, r）が含まれる区間を返す
    // 存在しない場合[-TIN, -TINF）を返す
	pair<T, T> covered_by(T l, T r) {
		assert(l < r);
		auto itr = prev(st.lower_bound({l + 1, -TINF}));
		if(itr->first <= l and r <= itr->second) return *itr;
		return make_pair(-TINF, -TINF);
	}

	// [x, x+1）が含まれる区間を返す
    // 存在しない場合[-TIN, -TINF）を返す
	pair<T, T> covered_by(T x) { return covered_by(x, x); }

    // [l, r)を追加する
    // 追加したときの増分を返す
	T insert(T l, T r) {
		if(l >= r) return 0;
		auto itr = prev(st.lower_bound({l + 1, -TINF}));
		if(itr->first <= l and r <= itr->second) return T(0);
		T sum_erased = T(0);
		if(itr->first <= l and l <= itr->second) {
			l = itr->first;
			sum_erased += itr->second - itr->first;
			itr = st.erase(itr);
		} else
			itr = next(itr);
		while(r > itr->second) {
			sum_erased += itr->second - itr->first;
			itr = st.erase(itr);
		}
		if(itr->first <= r) {
			sum_erased += itr->second - itr->first;
			r = itr->second;
			st.erase(itr);
		}
		st.emplace(l, r);
		return r - l - sum_erased;
	}

    // [x, x+1)を追加する
    // 追加したときの増分を返す
	T insert(T x) { return insert(x, x + 1); }

	// [l, r)を消す
    // 消したときの差分を返す
	T erase(T l, T r) {
		assert(l < r);
		auto itr = prev(st.lower_bound({l + 1, -TINF}));
		if(itr->first <= l and r <= itr->second) {
			if(itr->first < l) st.emplace(itr->first, l);
			if(r < itr->second) st.emplace(r, itr->second);
			st.erase(itr);
			return r - l;
		}

		T ret = T(0);
		if(itr->first <= l and l < itr->second) {
			ret += itr->second - l;
			if(itr->first < l) st.emplace(itr->first, l);
			itr = st.erase(itr);
		} else
			itr = next(itr);
		while(itr->second <= r) {
			ret += itr->second - itr->first;
			itr = st.erase(itr);
		}
		if(itr->first < r) {
			ret += r - itr->first;
			st.emplace(r, itr->second);
			st.erase(itr);
		}
		return ret;
	}

	// [x, x+1)を消す
    // 消したときの差分を返す
	T erase(T x) { return erase(x, x + 1); }

	int size() { return (int)st.size() - 2; }

	int mex(T x = 0) {
		auto itr = prev(st.lower_bound({x + 1, -TINF}));
		if(itr->first <= x and x < itr->second)
			return itr->second;
		else
			return x;
	}

	set<pair<T, T>> get() {
		set<pair<T, T>> res;
		for(auto &p : st) {
			if(abs(p.first) == TINF) continue;
			res.emplace(p.first, p.second + 1);
		}
		return res;
	}

    // 区間が覆っている要素数の総和を返す
	T sum_all() const {
		T res = 0;
		for(auto &p : st) {
			if(abs(p.first) == TINF) continue;
			res += p.second - p.first;
		}
		return res;
	}
};

void solve(){
    ll D, Q;
    cin >> D >> Q;
    RangeSet<ll> rs;
    ll ma = 0;
    REP(i,Q){
        ll A, B;
        cin >> A >> B;
        rs.insert(A, B+1);
        auto [l, r] = rs.covered_by(A, B+1);
        chmax(ma, r-l);
        cout << ma << endl;
    }
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    // int T; cin >> T; REP(t,T) solve();
}