N, M = map(int, input().split()) n = N - 1 pp = set() mm = set() ans = 0 for _ in range(M): x, y = map(int, input().split()) x -= 1 y -= 1 p = x + y m = x - y if p not in pp: pp.add(p) ans += N - abs(p - n) if m not in mm: mm.add(m) ans += N - abs(m) pp = sorted(pp) mm = sorted(mm) pp = sorted([n - abs(n - a) for a in pp]) mm = sorted([abs(a) for a in mm]) ppe = [a for a in pp if a % 2 == 0] ppo = [a for a in pp if a % 2 == 1] mme = [a for a in mm if a % 2 == 0] mmo = [a for a in mm if a % 2 == 1] def calc(pp, mm): SS = sorted(set(pp + mm)) IA = {a: i for i, a in enumerate(SS)} pp = [IA[a] for a in pp] mm = [IA[a] for a in mm] C = [0] * (len(SS) + 1) for a in mm: C[a] += 1 for i in range(len(SS)): C[i+1] += C[i] ret = 0 for a in pp: ret += C[a] return ret ans -= calc(ppe, mme) + calc(ppo, mmo) print(ans)