from bisect import bisect_left, bisect_right
import sys
input = sys.stdin.readline

n, m = map(int, input().split())
xst = set([]);	yst = set([])
for _ in [0] * m:
	X, Y = map(int, input().split())
	X -= 1;	Y -= 1
	xst.add(X + Y)
	yst.add(X - Y)

xlis = [[] for _ in [0] * 2]
ylis = [[] for _ in [0] * 2]
for x in sorted(xst):
	b = abs(x) & 1
	xlis[b].append(x)
for y in sorted(yst):
	b = abs(y) & 1
	ylis[b].append(y)

num = dc = 0
for x in xst:
	b = abs(x) & 1
	num += min(x, n - 1) - max(-n + 1 + x, 0) + 1
	l = bisect_left(ylis[b], max(-x, x - 2 * (n - 1)))
	r = bisect_right(ylis[b], min(2 * (n - 1) - x, x))
	dc += r - l
for y in yst:
	b = abs(y) & 1
	num += min(n - 1 + y, n - 1) - max(y, 0) + 1
	l = bisect_left(xlis[b], max(y, -y))
	r = bisect_right(xlis[b], min(2 * (n - 1) - y, 2 * (n - 1) + y))
	dc += r - l

ans = num - dc // 2
print(ans)