class LazySegTree:
    # RMQ and RUQ
    def __init__(self, init_val, seg_ide, lazy_ide, segfunc):
        self.n = len(init_val)
        self.num = 2**(self.n-1).bit_length()

        self.seg_ide = seg_ide
        self.lazy_ide = lazy_ide

        self.segfunc = segfunc

        # seg, lazy: 1-indexed
        self.seg = [seg_ide]*2*self.num
        for i in range(self.n):
            self.seg[i+self.num] = init_val[i]
        for i in range(self.num-1, 0, -1):
            self.seg[i] = self.segfunc(self.seg[2*i], self.seg[2*i+1])

        self.lazy = [lazy_ide]*2*self.num

    def gindex(self, l, r):
        # l, r: 1-indexed
        L = l + self.num
        R = r + self.num
        lm = (L // (L & -L)) >> 1
        rm = (R // (R & -R)) >> 1
        while L < R:
            if R <= rm:
                yield R
            if L <= lm:
                yield L
            L = L >> 1
            R = R >> 1
        while L:
            yield L
            L = L >> 1

    def propagate(self, *ids):
        # ids: 1-indexed
        for i in reversed(ids):
            v = self.lazy[i]
            if v is None:
                continue
            self.lazy[2*i] = self.lazy[2*i+1] = self.seg[2*i] = self.seg[2*i+1] = v
            self.lazy[i] = None

    def update(self, l, r, x):
        # l, r: 0-indexed
        # change x to [l, r)
        *ids, = self.gindex(l, r)
        self.propagate(*ids)
        L = l + self.num
        R = r + self.num
        while L < R:
            if R & 1:
                R -= 1
                self.lazy[R] = self.seg[R] = x
            if L & 1:
                self.lazy[L] = self.seg[L] = x
                L += 1
            L = L >> 1
            R = R >> 1
        for i in ids:
            # i: 1-indexed
            self.seg[i] = self.segfunc(self.seg[2*i], self.seg[2*i+1])

    def query(self, l, r):
        # l, r: 0-indexed
        # query for [l, r)
        if r <= l:
            return self.seg_ide

        self.propagate(*self.gindex(l, r))
        L = l + self.num
        R = r + self.num
        res = self.seg_ide
        while L < R:
            if R & 1:
                R -= 1
                res = self.segfunc(res, self.seg[R])
            if L & 1:
                res = self.segfunc(res, self.seg[L])
                L += 1
            L = L >> 1
            R = R >> 1
        return res

def segfunc(x, y):
    if x <= y:
        return x
    else:
        return y

INF = 10**18

import sys
import io, os
#input = sys.stdin.buffer.readline
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

def main():

    n, q = map(int, input().split())

    R = LazySegTree([n-1]*n, INF, None, segfunc)
    C = LazySegTree([n-1]*n, INF, None, segfunc)

    ans = (n-2)**2
    l = n
    u = n
    for i in range(q):
        t, x = map(int, input().split())
        x -= 1
        if t == 1:
            r = R.query(x, x+1)
            #print(i+1, r)
            ans -= (r-1)
            if x < l:
                C.update(0, r+1, x)
                l = x
        else:
            c = C.query(x, x+1)
            #print(i+1, c)
            ans -= (c-1)
            if x < u:
                R.update(0, c+1, x)
                u = x

    print(ans)

if __name__ == '__main__':
    main()


Measured memory_bytes: 93740