d = int(input())

ans = d
res = d // 2

for val in range(d // 2, d // 2 + 100000):
    val0 = val
    tmp = val
    val = val >> 1
    while val:
        tmp += val
        if tmp == d:
            ans = min(ans, val0)
            break
        val = val >> 1
print(ans)