import sys
input = sys.stdin.readline
from collections import *

N, S = map(int, input().split())
N += 1
fact = [1]

for i in range(1, S):
    fact.append(fact[-1]*i)

p = []

for i in range(S):
    for j in range(S):
        if j not in p:
            if N-fact[S-i-1]>0:
                N -= fact[S-i-1]
            else:
                p.append(j)
                break

pi = [(p[i], i) for i in range(S)]
pi.sort()
rev_p = [i for p, i in pi]
ans = 0
s = set()

for i in range(S):
    c = 0
    
    for j in range(rev_p[i]):
        if j not in s:
            c += 1
    
    ans += c*fact[S-i-1]
    s.add(rev_p[i])

print(ans)