def check(x,D):
    res=0
    while(x):
        res+=x
        x//=2
        if res==D:
            return True
    if res==D:
        return True
    else:
        return False

D=int(input())
ans=D
for x in range(D//2,D//2+100000):
    if check(x,D):
        ans=min(ans,x)
print(ans)