# Original solution
import sys


class SegmentTree():
    """
    update, get を提供するSegmentTree

    Attributes
    ----------
    __n : int
        葉の数。2 ^ i - 1
    __dot :
        Segment function
    __e: int
        単位元
    __node: list
        Segment Tree
    """
    def __init__(self, A, dot, e):
        """
        Parameters
        ----------
        A : list
            対象の配列
        dot :
            Segment function
        e : int
            単位元
        """
        n = 2 ** (len(A) - 1).bit_length()
        self.__n = n
        self.__dot = dot
        self.__e = e
        self.__node = [e] * (2 * n)
        for i in range(len(A)):
            self.__node[i + n] = A[i]
        for i in range(n - 1, 0, -1):
            self.__node[i] = self.__dot(self.__node[2 * i], self.__node[2 * i + 1])
    
    def update(self, i, c):
        i += self.__n
        node = self.__node
        node[i] = self.__dot(node[i], c)
        while i > 1:
            i //= 2
            node[i] = self.__dot(node[2 * i], node[2 * i + 1])

    def get(self, l, r):
        vl, vr = self.__e, self.__e
        l += self.__n
        r += self.__n
        while (l < r):
            if l & 1:
                vl = self.__dot(vl, self.__node[l])
                l += 1
            l //= 2
            if r & 1:
                r -= 1
                vr = self.__dot(vr, self.__node[r])
            r //= 2
        return self.__dot(vl, vr)


N, Q = list(map(int, input().split()))
query = [tuple(map(int, sys.stdin.readline().split())) for _ in range(Q)]

flagH = [N - 1] * N
flagW = [N - 1] * N

stH = SegmentTree([N - 1] * N, min, N - 1)
stW = SegmentTree([N - 1] * N, min, N - 1)

cnt = 0
for t, x in query:
    if t == 1:
        flagX, flagY = flagW, flagH
        stX, stY = stW, stH
    else:
        flagX, flagY = flagH, flagW
        stX, stY = stH, stW

    cnt += max(0, min(stX.get(x - 1, N), flagX[x - 1]) - 1)
    # flagX[x - 1] = 0
    stY.update(stX.get(x - 1, N), x - 1)

print((pow(N - 2, 2) - cnt))


# Optimized solution
import sys


class SegmentTree():
    """
    update, get を提供するSegmentTree

    Attributes
    ----------
    __n : int
        葉の数。2 ^ i - 1
    __dot :
        Segment function
    __e: int
        単位元
    __node: list
        Segment Tree
    """
    def __init__(self, A, dot, e):
        """
        Parameters
        ----------
        A : list
            対象の配列
        dot :
            Segment function
        e : int
            単位元
        """
        n = 2 ** (len(A) - 1).bit_length()
        self.__n = n
        self.__dot = dot
        self.__e = e
        self.__node = [e] * (2 * n)
        for i in range(len(A)):
            self.__node[i + n] = A[i]
        for i in range(n - 1, 0, -1):
            self.__node[i] = self.__dot(self.__node[2 * i], self.__node[2 * i + 1])
    
    def update(self, i, c):
        i += self.__n
        node = self.__node
        node[i] = self.__dot(node[i], c)
        while i > 1:
            i //= 2
            node[i] = self.__dot(node[2 * i], node[2 * i + 1])

    def get(self, l, r):
        vl, vr = self.__e, self.__e
        l += self.__n
        r += self.__n
        while (l < r):
            if l & 1:
                vl = self.__dot(vl, self.__node[l])
                l += 1
            l //= 2
            if r & 1:
                r -= 1
                vr = self.__dot(vr, self.__node[r])
            r //= 2
        return self.__dot(vl, vr)


N, Q = list(map(int, input().split()))
query = [tuple(map(int, sys.stdin.readline().split())) for _ in range(Q)]

flagH = [N - 1] * N
flagW = [N - 1] * N

stH = SegmentTree([N - 1] * N, min, N - 1)
stW = SegmentTree([N - 1] * N, min, N - 1)

cnt = 0
for t, x in query:
    if t == 1:
        stX, stY = stW, stH
    else:
        stX, stY = stH, stW

    cnt += max(0, stX.get(x - 1, N) - 1)
    # flagX[x - 1] = 0
    stY.update(stX.get(x - 1, N), x - 1)

print((pow(N - 2, 2) - cnt))