20231210

# def f(a, b):

# global memo

# if memo[a-1][b-1] != 0:

# return memo[a-1][b-1]

# if a == 1 or b == 1:

# memo[a-1][b-1] = 1

# return 1

# memo[a-1][b-1] = (f(a - 1, b) + f(a, b - 1)) % 100000000

# return memo[a-1][b-1]

#

#

# r, c = map(int, input().split())

# memo = []

# for i in range(r):

# v = [0] * c

# memo.append(v)

# print(f(r, c))

'''

Class ?

function(기능) + Variable(변수)

'''

import logging

# class student:

# def init(self, name, height, talkk):

# self.name = name

# self.height = height

# self.talkk = talkk

#

# def talk(self):

# self.x = 10

# print('Hello Im student', 'Im', self.name)

#

#

# x = student('Ike', 177, 'Hello')

# x.talk()

# n = int(input())

# d = list(map(int, input().split()))

# max = 0

# min = 1000

# for i in range(n):

# if d[i] > max:

# max = d[i]

# if d[i] < min:

# min = d[i]

# print(max-min)

# class save:

# def init(self, n, datas):

# self.n = n

# self.datas = datas

#

# def convert(self):

# for i in range(self.n):

# self.datas[i] = int(self.datas[i])

#

# def findMax(self):

#

#

# def findMin(self):

#

#

# n = int(input())

# data = input().split()

# x = save(n, data)

#

# x.convert()

# class a:

# def init(self, x, y):

# self.x = x

# self.y = y

#

# def null(self):

# if x[0] > y[2] or x[1] > y[3] or y[0] > x[2] or y[1] > x[3]:

# return 1

# return 0

#

# def point(self):

# if x[0] == y[2] and x[1] == y[3]:

# return 1

# if x[2] == y[0] and x[3] == y[1]:

# return 1

# if x[0] == y[2] and x[3] == y[1]:

# return 1

# if x[2] == y[0] and x[1] == y[3]:

# return 1

# return 0

#

# def line(self):

# if x[0] == y[2] or x[1] == y[3] or x[2] == y[0] or x[3] == y[1]:

# return 1

# return 0

#

#

# x = list(map(int, input().split()))

# y = list(map(int, input().split()))

# k = a(x, y)

#

# if k.null() == 1:

# print('NULL')

# else:

# if k.point() == 1:

# print('POINT')

# else:

# if k.line() == 1:

# print('LINE')

# else:

# print('FACE')

# class a:

# def init(self, d1, d2):

# self.d1 = d1

# self.d2 = d2

#

# def gcd(self, a, b):

# if a == 0:

# return b

# return x.gcd(b % a, a)

#

# def sum(self):

# su = 0

# for i in range(d1, d2 + 1, 1):

# su = su + i

# return su

#

# def count(self):

# s = 0

# for i in range(d1, d2, 1):

# for j in range(i + 1, d2 + 1, 1):

# s = s + x.gcd(i, j) - 1

# return s

#

#

# d1, d2 = map(int, input().split())

# x = a(d1, d2)

# sumd = x.sum()

# print(sumd - x.count() - d2 + d1)

# class a:

# def init(self, n, m):

# self.n = n

# self.m = m

#

# def f(self, k):

# if m[k] != 0:

# return m[k]

# if k == 1:

# m[k] = 1

# return 1

# if k == 2:

# m[k] = 2

# return 2

# m[k] = (x.f(k-1) + x.f(k - 2)) % 100000007

# return m[k]

#

#

# n = int(input())

# m = [0] * (n+2)

# x = a(n, m)

# print(x.f(n))

# import sys

# limit_number = 2000000

# sys.setrecursionlimit(limit_number)

#

# class recursion:

# def init(self, x):

# self.x = x

# self.data = [0] * 10002

#

# def execute(self, k):

# if self.data[k] != 0:

# return self.data[k]

# if k == 1:

# self.data[k] = 1

# return 1

# if k == 2:

# self.data[k] = 2

# return 2

# self.data[k] = (rec.execute(k-1) + rec.execute(k-2)) % 100000007

# return self.data[k]

#

#

# x = int(input())

# rec = recursion(x)

# print(rec.execute(x))

# class a:

# def init(self, n):

# self.n = n

#

# def f(self):

# s = 1

# for i in range(n//3):

# s = s * 2

# return s % 100000007

#

#

# n = int(input())

# x = a(n)

# if n % 3 != 0:

# print(0)

# else:

# print(x.f())

# n = int(input())

# d = list(map(int, input().split()))

# for i in range(n-1, -1, -1):

# print(d[i], end=' ')

# d = list(map(int, input()))

# for i in range(len(d)-1, -1, -1):

# print(d[i], end='')

# def f(a, b):

# if a == 0:

# return b

# return f(b % a, a)

#

#

# a, b = map(int, input().split())

# print(f(a, b))

def f(n, r):

global s

if r == 0:

return 1

f(n, r-1)

s = s * (n-r+1)

def g(n, r):

global s

if r == 0:

return

f(n, r-1)

s = s // r

s = 1

n, r = map(int, input().split())

f(n, r)

g(n, r)

print(s)