import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N,S = MI()

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

X = []
flag = [0]*(S+1)
for i in range(S):
    r = 1
    while N >= factorial[S-i-1]:
        N -= factorial[S-i-1]
        r += 1
    for i in range(1,S+1):
        if r == 1 and flag[i] == 0:
            flag[i] = 1
            X.append(i)
            break
        elif flag[i] == 0:
            r -= 1

Y = [0]*S
for i in range(S):
    Y[X[i]-1] = i+1

ans = 0
flag = [0]*(S+1)
for i in range(S):
    y = Y[i]
    a = sum(flag[1:y])
    ans += factorial[S-1-i]*(y-1-a)
    flag[y] = 1

print(ans)