import sys
sys.setrecursionlimit(1000000000)

#
# Solution Template for Buried Treasure
# 
# Australian Informatics Olympiad 2025
# 
# This file is provided to assist with reading of input and writing of output
# for the problem. You may modify this file however you wish, or
# you may choose not to use this file at all.
#

# N is the number of clues.
N = 0
# L is the number of locations.
L = 0

# A and B contain clues. Note that the lists start from 0, and so the first
# clue is (A[0], B[0]) and the last clue is (A[N-1], B[N-1]).
A = []
B = []

# Read the values of N, L, and the clues.
N, L = map(int, input().strip().split())
for i in range(0, N):
  input_vars = list(map(int, input().strip().split()))
  A.append(input_vars[0])
  B.append(input_vars[1])

# TODO: This is where you should compute your solution. Store the number of
# locations that are consistent with all N clues into the variable answer.

answer = 0

# Write the answer.
print(answer)