import math
import sys

args = sys.stdin.readline().split()
n, r = int(args[0]), int(args[1])
cows = []
for i in range(n):
    line = sys.stdin.readline().split()
    cows.append((int(line[0]), int(line[1])))

def distance(f, t):
    x = t[0] - f[0]
    y = t[1] - f[1]
    return math.sqrt(x*x + y*y)

def backtrack(visited, i, cost, limit, res):

    if i in visited:
        return res

    visited.append(i)

    f = cows[i]

    m = res
    for j in range(n):
        if j == i:
            continue

        t = cows[j]
        d = distance(f, t)

        if cost + d >= limit:
            continue

        v = backtrack(visited, j, cost + d, limit, res + 1)

        m = max(m, v)
    visited.remove(i)

    return m


print(max([backtrack([],s, 0, r, 0) for s in range(n)]))