N = int(input())
ans = N
for j in range(60+1):
    high = N
    low = 1
    while high-low>1:
        mid = (high+low)//2
        if pow(mid,j)<=N:
            low = mid
        else:
            high = mid
    ans = min(ans,low+j+N-pow(low,j))
print(ans)