#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


class UnionFind:
    def __init__(self, N):
        self.root = list(range(N))
        self.size = [1] * (N)
        self.left_end = list(range(N))
        self.right_end = list(range(N))

    def find_root(self, x):
        root = self.root
        while root[x] != x:
            root[x] = root[root[x]]
            x = root[x]
        return x

    def merge(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return False
        sx, sy = self.size[x], self.size[y]
        if sx < sy:
            self.root[x] = y
            self.size[y] += sx
            self.left_end[y] = min(self.left_end[x], self.left_end[y])
            self.right_end[y] = max(self.right_end[x], self.right_end[y])
        else:
            self.root[y] = x
            self.size[x] += sy
            self.left_end[x] = min(self.left_end[x], self.left_end[y])
            self.right_end[x] = max(self.right_end[x], self.right_end[y])
        return True


D, Q = map(int, readline().split())
m = map(int, read().split())
A, B = zip(*zip(m, m))
B = tuple(b + 1 for b in B)

X = sorted(set(A + B))
x_to_i = {v: i for i, v in enumerate(sorted(set(A + B)))}

uf = UnionFind(len(X))
find = uf.find_root
merge = uf.merge
answer = 0
for a, b in zip(A, B):
    a = x_to_i[a]
    b = x_to_i[b]
    a = uf.right_end[find(a)]
    b = uf.left_end[find(b)]
    while a < b:
        merge(a, a + 1)
        a = uf.right_end[find(a)]
    b = find(b)
    width = X[uf.right_end[b]] - X[uf.left_end[b]]
    if answer < width:
        answer = width
    print(answer)