from math import inf, log2


class SegmentTree:
    def __init__(self, array, func=max):
        self.n = len(array)
        self.size = 2**(int(log2(self.n-1))+1) if self.n != 1 else 1
        self.func = func
        self.default = 0 if self.func != min else inf
        self.data = [self.default] * (2 * self.size)
        self.process(array)

    def process(self, array):
        self.data[self.size : self.size+self.n] = array
        for i in range(self.size-1, -1, -1):
            self.data[i] = self.func(self.data[2*i], self.data[2*i+1])

    def query(self, alpha, omega):
        """Returns the result of function over the range (inclusive)!"""
        if alpha == omega:
            return self.data[alpha + self.size]
        res = self.default
        alpha += self.size
        omega += self.size + 1
        while alpha < omega:
            if alpha & 1:
                res = self.func(res, self.data[alpha])
                alpha += 1
            if omega & 1:
                omega -= 1
                res = self.func(res, self.data[omega])
            alpha >>= 1
            omega >>= 1
        return res

    def update(self, index, value):
        """Updates the element at index to given value!"""
        index += self.size
        self.data[index] = value
        index >>= 1
        while index:
            self.data[index] = self.func(self.data[2*index], self.data[2*index+1])
            index >>= 1


# ------------------- fast io --------------------
import os
import sys
from io import BytesIO, IOBase

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")

# ------------------- fast io --------------------
from math import gcd, ceil

def pre(s):
    n = len(s)
    pi = [0] * n
    for i in range(1, n):
        j = pi[i - 1]
        while j and s[i] != s[j]:
            j = pi[j - 1]
        if s[i] == s[j]:
            j += 1
        pi[i] = j
    return pi


def prod(a):
    ans = 1
    for each in a:
        ans = (ans * each)
    return ans

def lcm(a, b): return a * b // gcd(a, b)


def binary(x, length=16):
    y = bin(x)[2:]
    return y if len(y) >= length else "0" * (length - len(y)) + y

from math import log2


class SegmentTree:
    def __init__(self, array):
        self.n = len(array)
        self.size = 2**(int(log2(self.n-1))+1) if self.n != 1 else 1
        self.default = 10**18
        self.data = [self.default] * (2 * self.size)
        self.process(array)

    def process(self, array):
        self.data[self.size : self.size+self.n] = array

    def query(self, index):
        """Returns the value at given index!"""
        res = self.default
        index += self.size
        while index:
            res = min(res, self.data[index])
            index >>= 1
        return res

    def update(self, alpha, omega, value):
        """Increases all elements in the range (inclusive) by given value!"""
        alpha += self.size
        omega += self.size + 1
        while alpha < omega:
            if alpha & 1:
                self.data[alpha] = min(self.data[alpha], value)
                alpha += 1
            if omega & 1:
                omega -= 1
                self.data[omega] = min(self.data[omega], value)
            alpha >>= 1
            omega >>= 1

for _ in range(int(input()) if not True else 1):
    n, q = map(int, input().split())
    black = (n-2)*(n-2)
    first_in_row = [n-1]*n
    first_in_row[n-1] = 0
    first_in_column = [n-1]*n
    first_in_column[n-1] = 0
    #print(black, first_in_row, first_in_column)
    first_in_row = SegmentTree(first_in_row)
    first_in_column = SegmentTree(first_in_column)
    for __ in range(q):
        x, y = map(int, input().split())
        if x == 1:
            # go down
            col_first = first_in_column.query(y-1)
            black -= max(col_first - 1, 0)
            first_in_row.update(0, col_first-1, y-1)
            first_in_column.update(y-1, y-1, 0)
        else:
            # go right
            row_first = first_in_row.query(y-1)
            black -= max(row_first - 1, 0)
            first_in_column.update(0, row_first-1, y-1)
            first_in_row.update(y-1, y-1, 0)
        #print(black, first_in_row, first_in_column)
    print(black)

Measured memory_bytes: 85940