mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    N = int(input())
    if N == 1:
        print(1)
        exit()
    ans = N
    for j in range(1, 70):
        ok = 1
        ng = N+1
        mid = (ok + ng) // 2
        while ng - ok > 1:
            val = 1
            for _ in range(j):
                val *= mid
                if val > N:
                    break
            if val <= N:
                ok = mid
            else:
                ng = mid
            mid = (ok + ng) // 2
        ans = min(ok + j + (N - ok ** j), ans)
    print(ans)


if __name__ == '__main__':
    main()