#!/usr/bin/env python3
n, k = map(int, input().split())
algs, stack = {tuple(zip(*(map(int, input().split()) for _ in ".."))) for _ in range(n)}, [[(0, 0) for _ in range(k)]]
while stack:
    base = stack.pop()
    add = {alg for alg in algs if all(l <= b for (a, b), (l, h) in zip(base, alg))}
    stack.extend(add)
    algs = algs.difference(add)
print(n - len(algs))