n = int(input())
ans = n
for j in range(1, 70):
    l, r = 0, 10 ** (18 // j + 1)
    while r - l > 1:
        m = (l + r) // 2
        if pow(m, j) <= n:
            l = m
        else:
            r = m
    res = l + j + n - pow(l, j)
    if ans > res:
        ans = res
print(ans)