D = int(input())
ok = pow(10,18)*2
ng = 0

def check(x):
    ret = x
    while x > 0:
        x = x//2
        ret += x
    return ret
cnt = 0
while abs(ok-ng) > 1: #and cnt < 100:
    mid = (ok+ng)//2
    #print(ok,mid,ng)
    if check(mid) >= D:
        ok = mid
    else:
        ng = mid
    cnt += 1
ans = ok
#print(ans)

def verify(x,y):
    ret = x
    while x > 0:
        if ret == y:
            return True
        else:
            x = x//2
            ret += x
    if ret == y:
        return True
    else:
        return False
a = ans + 0
b = ans - 0

while True:
    if verify(a,D):
        print(a)
        break
    elif verify(b,D):
        print(b)
        break
    else:
        a += 1
        b -= 1