d = int(input())
ng = 0
ok = d

def  cal(a):
    cnt = 0
    while a:
        cnt += a
        a//=2
    return cnt

def  cal2(a):
    cnt = 0
    while a:
        cnt += a
        a//=2
        if cnt == d:
            return True
    return False

ans = d
while ok - ng > 1:
    mid = (ok + ng)//2
    if  cal(mid) >= d:
        ok = mid
    else:
        ng = mid

    if cal2(mid):
        ans = min(ans,mid)
        

print(ans)