import sys

input = sys.stdin.buffer.readline

ans = 0
d, q = map(int, input().split())

"""
this library is written by tatyam-san.
c.f. https://github.com/tatyam-prime/SortedSet
SS = SortedSet(A)
SS.len(): 長さ

x in SS: 含むかどうか
SS.add(x): xを加える
SS.discard(x): xを除く
SS.lt/le/gt/ge: 未満/以下/超/以上の要素を返す
SS[x]:下からx番目の要素
SS.index(x): x未満の要素の数、xが含まれていれば0-indexのidx
SS.index_rihgt(x): x以下の要素の数
SMS=SortedMultiSet(A)
だいたい同じ

SMS.count(x):xの数
"""
# https://github.com/tatyam-prime/SortedSet/blob/main/SortedMultiset.py
import math
from bisect import bisect_left, bisect_right, insort
from typing import Generic, Iterable, Iterator, List, TypeVar, Union

T = TypeVar("T")


class SortedMultiset(Generic[T]):
    BUCKET_RATIO = 50

    REBUILD_RATIO = 170

    def _build(self, a=None) -> None:
        "Evenly divide `a` into buckets."

        if a is None:
            a = list(self)
        size = self.size = len(a)
        bucket_size = int(math.ceil(math.sqrt(size / self.BUCKET_RATIO)))
        self.a = [
            a[size * i // bucket_size : size * (i + 1) // bucket_size]
            for i in range(bucket_size)
        ]

    def __init__(self, a: Iterable[T] = []) -> None:
        "Make a new SortedMultiset from iterable. / O(N) if sorted / O(N log N)"

        a = list(a)
        if not all(a[i] <= a[i + 1] for i in range(len(a) - 1)):
            a = sorted(a)
        self._build(a)

    def __iter__(self) -> Iterator[T]:
        for i in self.a:

            for j in i:
                yield j

    def __reversed__(self) -> Iterator[T]:
        for i in reversed(self.a):

            for j in reversed(i):
                yield j

    def __len__(self) -> int:
        return self.size

    def __repr__(self) -> str:
        return "SortedMultiset" + str(self.a)

    def __str__(self) -> str:
        s = str(list(self))

        return "{" + s[1 : len(s) - 1] + "}"

    def _find_bucket(self, x: T) -> List[T]:
        "Find the bucket which should contain x. self must not be empty."

        for a in self.a:
            if x <= a[-1]:
                return a
        return a

    def __contains__(self, x: T) -> bool:
        if self.size == 0:

            return False
        a = self._find_bucket(x)
        i = bisect_left(a, x)
        return i != len(a) and a[i] == x

    def count(self, x: T) -> int:
        "Count the number of x."

        return self.index_right(x) - self.index(x)

    def add(self, x: T) -> None:
        "Add an element. / O(√N)"

        if self.size == 0:
            self.a = [[x]]
            self.size = 1
            return
        a = self._find_bucket(x)
        insort(a, x)
        self.size += 1
        if len(a) > len(self.a) * self.REBUILD_RATIO:
            self._build()

    def discard(self, x: T) -> bool:
        "Remove an element and return True if removed. / O(√N)"

        if self.size == 0:
            return False
        a = self._find_bucket(x)
        i = bisect_left(a, x)
        if i == len(a) or a[i] != x:
            return False
        a.pop(i)
        self.size -= 1
        if len(a) == 0:
            self._build()
        return True

    def lt(self, x: T) -> Union[T, None]:
        "Find the largest element < x, or None if it doesnt exist."

        for a in reversed(self.a):
            if a[0] < x:
                return a[bisect_left(a, x) - 1]

    def le(self, x: T) -> Union[T, None]:
        "Find the largest element <= x, or None if it doesnt exist."

        for a in reversed(self.a):
            if a[0] <= x:
                return a[bisect_right(a, x) - 1]

    def gt(self, x: T) -> Union[T, None]:
        "Find the smallest element > x, or None if it doesnt exist."

        for a in self.a:
            if a[-1] > x:
                return a[bisect_right(a, x)]

    def ge(self, x: T) -> Union[T, None]:
        "Find the smallest element >= x, or None if it doesnt exist."

        for a in self.a:
            if a[-1] >= x:
                return a[bisect_left(a, x)]

    def __getitem__(self, x: int) -> T:
        "Return the x-th element, or IndexError if it doesnt exist."

        if x < 0:
            x += self.size
        if x < 0:
            raise IndexError
        for a in self.a:
            if x < len(a):
                return a[x]
            x -= len(a)
        raise IndexError

    def index(self, x: T) -> int:
        "Count the number of elements < x."

        ans = 0
        for a in self.a:
            if a[-1] >= x:
                return ans + bisect_left(a, x)
            ans += len(a)
        return ans

    def index_right(self, x: T) -> int:
        "Count the number of elements <= x."

        ans = 0
        for a in self.a:
            if a[-1] > x:
                return ans + bisect_right(a, x)
            ans += len(a)
        return ans


# https://github.com/tatyam-prime/SortedSet/blob/main/SortedSet.py
# import math

# from bisect import bisect_left, bisect_right
# from typing import Generic, Iterable, Iterator, TypeVar, Union, List
# T = TypeVar('T')


class SortedSet(Generic[T]):
    BUCKET_RATIO = 50

    REBUILD_RATIO = 170

    def _build(self, a=None) -> None:
        "Evenly divide `a` into buckets."

        if a is None:
            a = list(self)
        size = self.size = len(a)
        bucket_size = int(math.ceil(math.sqrt(size / self.BUCKET_RATIO)))
        self.a = [
            a[size * i // bucket_size : size * (i + 1) // bucket_size]
            for i in range(bucket_size)
        ]

    def __init__(self, a: Iterable[T] = []) -> None:
        "Make a new SortedSet from iterable. / O(N) if sorted and unique / O(N log N)"

        a = list(a)
        if not all(a[i] < a[i + 1] for i in range(len(a) - 1)):
            a = sorted(set(a))
        self._build(a)

    def __iter__(self) -> Iterator[T]:
        for i in self.a:

            for j in i:
                yield j

    def __reversed__(self) -> Iterator[T]:
        for i in reversed(self.a):

            for j in reversed(i):
                yield j

    def __len__(self) -> int:
        return self.size

    def __repr__(self) -> str:
        return "SortedSet" + str(self.a)

    def __str__(self) -> str:
        s = str(list(self))

        return "{" + s[1 : len(s) - 1] + "}"

    def _find_bucket(self, x: T) -> List[T]:
        "Find the bucket which should contain x. self must not be empty."

        for a in self.a:
            if x <= a[-1]:
                return a
        return a

    def __contains__(self, x: T) -> bool:
        if self.size == 0:

            return False
        a = self._find_bucket(x)
        i = bisect_left(a, x)
        return i != len(a) and a[i] == x

    def add(self, x: T) -> bool:
        "Add an element and return True if added. / O(√N)"

        if self.size == 0:
            self.a = [[x]]
            self.size = 1
            return True
        a = self._find_bucket(x)
        i = bisect_left(a, x)
        if i != len(a) and a[i] == x:
            return False
        a.insert(i, x)
        self.size += 1
        if len(a) > len(self.a) * self.REBUILD_RATIO:
            self._build()
        return True

    def discard(self, x: T) -> bool:
        "Remove an element and return True if removed. / O(√N)"

        if self.size == 0:
            return False
        a = self._find_bucket(x)
        i = bisect_left(a, x)
        if i == len(a) or a[i] != x:
            return False
        a.pop(i)
        self.size -= 1
        if len(a) == 0:
            self._build()
        return True

    def lt(self, x: T) -> Union[T, None]:
        "Find the largest element < x, or None if it doesnt exist."

        for a in reversed(self.a):
            if a[0] < x:
                return a[bisect_left(a, x) - 1]

    def le(self, x: T) -> Union[T, None]:
        "Find the largest element <= x, or None if it doesnt exist."

        for a in reversed(self.a):
            if a[0] <= x:
                return a[bisect_right(a, x) - 1]

    def gt(self, x: T) -> Union[T, None]:
        "Find the smallest element > x, or None if it doesnt exist."

        for a in self.a:
            if a[-1] > x:
                return a[bisect_right(a, x)]

    def ge(self, x: T) -> Union[T, None]:
        "Find the smallest element >= x, or None if it doesnt exist."

        for a in self.a:
            if a[-1] >= x:
                return a[bisect_left(a, x)]

    def __getitem__(self, x: int) -> T:
        "Return the x-th element, or IndexError if it doesnt exist."

        if x < 0:
            x += self.size
        if x < 0:
            raise IndexError
        for a in self.a:
            if x < len(a):
                return a[x]
            x -= len(a)
        raise IndexError

    def index(self, x: T) -> int:
        "Count the number of elements < x."

        ans = 0
        for a in self.a:
            if a[-1] >= x:
                return ans + bisect_left(a, x)
            ans += len(a)
        return ans

    def index_right(self, x: T) -> int:
        "Count the number of elements <= x."

        ans = 0
        for a in self.a:
            if a[-1] > x:
                return ans + bisect_right(a, x)
            ans += len(a)
        return ans


SS = SortedSet()

infi = 1 << 80  # 10 ** 9 相当

# banpe
SS.add((-infi, -infi))
SS.add((infi, infi))


def is_covered(left, right, SS):
    temp = SS.le((left + 1, left + 1))
    return temp[0] <= left and right <= temp[1]


def covered_by_kukan(left, right, SS):
    temp = SS.le((left + 1, left + 1))
    if temp[0] <= left and right <= temp[1]:
        return temp
    return (-infi, -infi)


def covered_by_point(x, SS):
    return covered_by_kukan(x, x, SS)


# insertして、増加分を返す
def insert(left, right, SS):
    global ans
    temp = SS.lt((left + 1, left + 1))
    idx = SS.index(temp)  # 二度手間
    if temp[0] <= left and right <= temp[1]:
        return 0
    temp_erased = 0
    # わかりにくいけど、tempが左端より左から始まって、
    # くっつくか、left<temp.1<rightのとき
    # これだと区間が合体する
    if temp[0] <= left and left <= temp[1] + 1:
        left = temp[0]
        temp_erased += temp[1] - temp[0] + 1
        # erase(temp[0], temp[1], SS)
        SS.discard(temp)
    # 合体しないときはiter++とする
    else:
        idx += 1
    temp = SS[idx]
    while right > temp[1]:
        temp_erased += temp[1] - temp[0] + 1
        SS.discard(temp)
        # 多分eraseしたのと打ち消してidxはそのままでよいはず
        temp = SS[idx]
    # print("temp", temp, "leftright", left, right)
    if temp[0] - 1 <= right and right <= temp[1]:
        temp_erased += temp[1] - temp[0] + 1
        right = temp[1]
        SS.discard(temp)
    SS.add((left, right))
    ans = max(right - left + 1, ans)
    return right - left + 1 - temp_erased


# def erase(left,right,SS):


for _ in range(q):
    a, b = map(int, input().split())
    insert(a, b, SS)
    # print("i", _, "SS", SS)
    print(ans)