def greedy(N,K):
    X=[0]*(N+1); X[K]=1
    S=[K]

    for _ in range(N-1):
        alpha=-1; I=0
        for k in range(1,N+1):
            if X[k]==1:
                continue

            beta=float("inf")
            for a in S:
                beta=min(beta,abs(k-a))

            if alpha<beta:
                alpha=beta
                I=k

        S.append(I)
    return S

N,K=map(int,input().split())

"""
for K in range(1,N+1):
    print(greedy(N,K))
"""

print(N-1 if K!=N-1 else N)