import sys
def input():
  return sys.stdin.readline()[:-1]
N=int(input())
M=int(input())
f=[1]
for i in range(30): f.append(f[-1]*(i+1))
if N==0:
  if M==0: print(1)
  else: print(0)
else:
  ans=[[]]
  for i in range(1,16):
    a=[0]
    for j in range(1,31):
      tmp=j**i
      for k in range(j):
        tmp-=a[k]*f[j]//f[k]//f[j-k]
      a.append(tmp)
    ans.append(a)
  if M>=len(ans[N]): print(0)
  else: print(ans[N][M])