D=int(input())
N=D.bit_length()

T=[pow(2,i) for i in range(N-1,-1,-1)]

M=D
for k in range(1,N+1):
    E=[sum(T[i:i+k]) for i in range(N)]

    S=0
    X=D

    for i in range(N):
        if E[i]<=X:
            X-=E[i]
            S+=pow(2,N-1-i)

    if X==0:
        M=min(M,S)
print(M)