using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = long.Parse(ReadLine());
        var ans = n;
        for (var j = 2; j < 64; ++j)
        {
            var ok = 0L;
            var ng = n;
            while (ng - ok > 1)
            {
                var mid = (ok + ng) / 2;
                if (IsOverN(mid, j, n)) ng = mid;
                else ok = mid;
            }
            var ij = 1L;
            for (var x = 0; x < j; ++x) ij *= ok;
            ans = Math.Min(ans, ok + j + n - ij);
        }
        WriteLine(ans);
    }
    static bool IsOverN(long i, int j, long n)
    {
        var prev = 1L;
        var ij = 1L;
        for (var x = 0; x < j; ++x)
        {
            ij *= i;
            if (prev >= ij || ij % i != 0) return true;
            prev = ij;
        }
        return ij > n;
    }
}