N = int(input())
if N == 1:
    print(2)
    exit()
if N == 2:
    print(3)
    exit()

inf = 10 ** 12

def f(v, p, d):
    val = 1
    for i in range(d - 1):
        val *= p
        val += 1
        if v * val >= inf:
            return v * val        
    return v * val

ans = N - 1
for d in range(2, 45):
    for v in range(1, 10**18):
        if f(v, v + 1, d) > N:
            break
        yes = v + 1
        no = N + 1
        while no - yes != 1:
            mid = (yes + no)//2
            if f(v, mid, d) <= N:
                yes = mid
            else:
                no  = mid
        if f(v, yes, d) == N:
            ans = min(ans, yes)

print(ans)