# ref:
# https://github.com/not522/ac-library-python/blob/a30b7e590271d7b77459946695ae8ce984e50f0a/atcoder/lazysegtree.py
import sys
import typing
def _ceil_pow2(n: int) -> int:
x = 0
while (1 << x) < n:
x += 1
return x
class LazySegTree:
def __init__(
self,
op: typing.Callable[[typing.Any, typing.Any], typing.Any],
e: typing.Any,
mapping: typing.Callable[[typing.Any, typing.Any], typing.Any],
composition: typing.Callable[[typing.Any, typing.Any], typing.Any],
id_: typing.Any,
v: typing.Union[int, typing.List[typing.Any]]) -> None:
self._op = op
self._e = e
self._mapping = mapping
self._composition = composition
self._id = id_
if isinstance(v, int):
v = [e] * v
self._n = len(v)
self._log = _ceil_pow2(self._n)
self._size = 1 << self._log
self._d = [e] * (2 * self._size)
self._lz = [self._id] * self._size
for i in range(self._n):
self._d[self._size + i] = v[i]
for i in range(self._size - 1, 0, -1):
self._update(i)
def set(self, p: int, x: typing.Any) -> None:
assert 0 <= p < self._n
p += self._size
for i in range(self._log, 0, -1):
self._push(p >> i)
self._d[p] = x
for i in range(1, self._log + 1):
self._update(p >> i)
def get(self, p: int) -> typing.Any:
assert 0 <= p < self._n
p += self._size
for i in range(self._log, 0, -1):
self._push(p >> i)
return self._d[p]
def prod(self, left: int, right: int) -> typing.Any:
assert 0 <= left <= right <= self._n
if left == right:
return self._e
left += self._size
right += self._size
for i in range(self._log, 0, -1):
if ((left >> i) << i) != left:
self._push(left >> i)
if ((right >> i) << i) != right:
self._push(right >> i)
sml = self._e
smr = self._e
while left < right:
if left & 1:
sml = self._op(sml, self._d[left])
left += 1
if right & 1:
right -= 1
smr = self._op(self._d[right], smr)
left >>= 1
right >>= 1
return self._op(sml, smr)
def all_prod(self) -> typing.Any:
return self._d[1]
def apply(self, left: int, right: typing.Optional[int] = None,
f: typing.Optional[typing.Any] = None) -> None:
assert f is not None
if right is None:
p = left
assert 0 <= left < self._n
p += self._size
for i in range(self._log, 0, -1):
self._push(p >> i)
self._d[p] = self._mapping(f, self._d[p])
for i in range(1, self._log + 1):
self._update(p >> i)
else:
assert 0 <= left <= right <= self._n
if left == right:
return
left += self._size
right += self._size
for i in range(self._log, 0, -1):
if ((left >> i) << i) != left:
self._push(left >> i)
if ((right >> i) << i) != right:
self._push((right - 1) >> i)
l2 = left
r2 = right
while left < right:
if left & 1:
self._all_apply(left, f)
left += 1
if right & 1:
right -= 1
self._all_apply(right, f)
left >>= 1
right >>= 1
left = l2
right = r2
for i in range(1, self._log + 1):
if ((left >> i) << i) != left:
self._update(left >> i)
if ((right >> i) << i) != right:
self._update((right - 1) >> i)
def max_right(
self, left: int, g: typing.Callable[[typing.Any], bool]) -> int:
assert 0 <= left <= self._n
assert g(self._e)
if left == self._n:
return self._n
left += self._size
for i in range(self._log, 0, -1):
self._push(left >> i)
sm = self._e
first = True
while first or (left & -left) != left:
first = False
while left % 2 == 0:
left >>= 1
if not g(self._op(sm, self._d[left])):
while left < self._size:
self._push(left)
left *= 2
if g(self._op(sm, self._d[left])):
sm = self._op(sm, self._d[left])
left += 1
return left - self._size
sm = self._op(sm, self._d[left])
left += 1
return self._n
def min_left(self, right: int, g: typing.Any) -> int:
assert 0 <= right <= self._n
assert g(self._e)
if right == 0:
return 0
right += self._size
for i in range(self._log, 0, -1):
self._push((right - 1) >> i)
sm = self._e
first = True
while first or (right & -right) != right:
first = False
right -= 1
while right > 1 and right % 2:
right >>= 1
if not g(self._op(self._d[right], sm)):
while right < self._size:
self._push(right)
right = 2 * right + 1
if g(self._op(self._d[right], sm)):
sm = self._op(self._d[right], sm)
right -= 1
return right + 1 - self._size
sm = self._op(self._d[right], sm)
return 0
def _update(self, k: int) -> None:
self._d[k] = self._op(self._d[2 * k], self._d[2 * k + 1])
def _all_apply(self, k: int, f: typing.Any) -> None:
self._d[k] = self._mapping(f, self._d[k])
if k < self._size:
self._lz[k] = self._composition(f, self._lz[k])
def _push(self, k: int) -> None:
self._all_apply(2 * k, self._lz[k])
self._all_apply(2 * k + 1, self._lz[k])
self._lz[k] = self._id
input = sys.stdin.readline
def main():
w, n = map(int, input().split())
def f(a, b):
return a if a > b else b
sg = LazySegTree(f, 0, f, f, 0, w)
for _ in range(n):
l, r = map(int, input().split())
l -= 1
x = sg.prod(l, r) + 1
print(x)
sg.apply(l, r, x)
if __name__ == "__main__":
main()