import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

class BitMax:
    def __init__(self, n):
        self.inf=10**9
        self.n = n + 3
        self.table = [-self.inf] * (self.n + 1)

    def update(self, i, x):
        i += 1
        while i <= self.n:
            if x > self.table[i]: self.table[i] = x
            i += i & -i

    def max(self, i):
        i += 1
        res = -self.inf
        while i > 0:
            if self.table[i] > res: res = self.table[i]
            i -= i & -i
        return res

class BitMin:
    def __init__(self, n):
        self.inf=10**9
        self.n = n + 3
        self.table = [self.inf] * (self.n + 1)

    def update(self, i, x):
        i += 1
        while i <= self.n:
            if x < self.table[i]: self.table[i] = x
            i += i & -i

    def min(self, i):
        i += 1
        res = self.inf
        while i > 0:
            if self.table[i] < res: res = self.table[i]
            i -= i & -i
        return res

d,q=MI()
s=set()
ab=[]
for _ in range(q):
    a,b=MI()
    b+=1
    ab.append((a,b))
    s.add(a)
    s.add(b)
dec=[a for a in sorted(s)]
enc={a:i for i,a in enumerate(dec)}
n=len(dec)

ll=BitMin(n)
rr=BitMax(n)
ans=0
for a,b in ab:
    a=enc[a]
    b=enc[b]
    ll.update(n-b,a)
    rr.update(a,b)
    l=ll.min(n-a)
    r=rr.max(b)
    ll.update(n-r,l)
    rr.update(l,r)
    ans=max(ans,dec[r]-dec[l])
    print(ans)