def akm(m,n): if m==0: return n+1 elif m>0 and n==0: return akm(m-1,1) elif m>0 and n>0: return akm(m-1,akm(m, n-1)) else: print('错误！') m,n=input().split() m=int(m) n=int(n) print(akm(m,n))