Problem:
Score: 300 points

Problem Statement

In 2028 and after a continuous growth, AtCoder Inc. finally built an empire with six cities (City 1, 2, 3, 4, 5, 6)!

There are five means of transport in this empire:

Train: travels from City 1 to 2 in one minute. A train can occupy at most A people.

Bus: travels from City 2 to 3 in one minute. A bus can occupy at most B people.

Taxi: travels from City 3 to 4 in one minute. A taxi can occupy at most C people.

Airplane: travels from City 4 to 5 in one minute. An airplane can occupy at most D people.

Ship: travels from City 5 to 6 in one minute. A ship can occupy at most E people.

For each of them, one vehicle leaves the city at each integer time (time 0, 1, 2, ...).

There is a group of N people at City 1, and they all want to go to City 6.

At least how long does it take for all of them to reach there?
You can ignore the time needed to transfer.

Constraints

1 \leq N, A, B, C, D, E \leq 10^{15}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A
B
C
D
E

Output

Print the minimum time required for all of the people to reach City 6, in minutes.

Sample Input 1

5
3
2
4
3
5

Sample Output 1

7

One possible way to travel is as follows.
First, there are N = 5 people at City 1, as shown in the following image:

In the first minute, three people travels from City 1 to City 2 by train. Note that a train can only occupy at most three people.

In the second minute, the remaining two people travels from City 1 to City 2 by train, and two of the three people who were already at City 2 travels to City 3 by bus. Note that a bus can only occupy at most two people.

In the third minute, two people travels from City 2 to City 3 by train, and another two people travels from City 3 to City 4 by taxi.

From then on, if they continue traveling without stopping until they reach City 6, all of them can reach there in seven minutes.

There is no way for them to reach City 6 in 6 minutes or less.

Sample Input 2

10
123
123
123
123
123

Sample Output 2

5

All kinds of vehicles can occupy N = 10 people at a time.
Thus, if they continue traveling without stopping until they reach City 6, all of them can reach there in five minutes.

Sample Input 3

10000000007
2
3
5
7
11

Sample Output 3

5000000008

Note that the input or output may not fit into a 32-bit integer type.

Solution in C# (Mono-mcs 6.8.0.105) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
//using System.Windows;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Atcoder
{
    public class Program
    {
        private static long mod = 1000000007;
        private static long max = 999999999999;

        static void Main(string[] args)
        {
            var n = Read().Decimal();
            var a = Read().Decimal();
            var b = Read().Decimal();
            var c = Read().Decimal();
            var d = Read().Decimal();
            var e = Read().Decimal();
            var min = Math.Min(a, b);
            min = Math.Min(min, c);
            min = Math.Min(min, d);
            min = Math.Min(min, e);
            var ans = Math.Ceiling(n / min) + 4;
            WriteRead(ans);
        }

        public static string Read()
        {
            return Console.ReadLine();
        }

        public static string[] ReadSplit()
        {
            return Console.ReadLine().Split(' ');
        }

        public static void WriteRead(object str)
        {
            Console.WriteLine(str);
            Read();
        }

        public static void Write(object str)
        {
            Console.WriteLine(str);
        }

        private static bool ChangeMin<T>(ref T a, T b) where T : IComparable
        {
            if (a.CompareTo(b) > 0)
            {
                a = b;
                return true;
            }
            return false;
        }

        private static bool ChangekMax<T>(ref T a, T b) where T : IComparable
        {
            if (b.CompareTo(a) > 0)
            {
                a = b;
                return true;
            }
            return false;
        }

        /*優先度付きキュー*/
        class PriorityQueue<T> where T : IComparable<T>
        {
            public readonly T[] Array;
            public readonly bool Greater;
            public int Count { get; private set; } = 0;

            public PriorityQueue(int capacity, bool greater = true)
            {
                this.Array = new T[capacity];
                this.Greater = greater;
            }

            public void Enqueue(T item)
            {
                this.Array[this.Count] = item;
                this.Count += 1;
                this.UpHeap();
            }

            public T Dequeue()
            {
                // 先頭要素を末尾にして再構成
                this.Swap(0, this.Count - 1);
                this.Count -= 1;
                this.DownHeap();

                return this.Array[this.Count];
            }


            private void UpHeap()
            {
                var n = this.Count - 1;
                while (n != 0)
                {
                    // 親要素の座標
                    var parent = (n - 1) / 2;

                    if (this.Compare(this.Array[n], this.Array[parent]) > 0)
                    {
                        this.Swap(n, parent);
                        n = parent;
                    }
                    else
                    {
                        break;
                    }
                }
            }

            private void DownHeap()
            {
                var parent = 0;
                while (true)
                {
                    var child = 2 * parent + 1;
                    if (child > this.Count - 1) break;

                    if (child < this.Count - 1 && this.Compare(this.Array[child], this.Array[child + 1]) < 0)
                    {
                        // 左より右の子のほうが大きい値の場合、右を入れ替え対象にする
                        child += 1;
                    }

                    if (this.Compare(this.Array[parent], this.Array[child]) < 0)
                    {
                        this.Swap(parent, child);
                        parent = child;
                    }
                    else
                    {
                        break;
                    }
                }
            }

            //aとbを比較する
            private int Compare(T a, T b)
            {
                var c = a.CompareTo(b);
                if (!this.Greater)
                {
                    c = -c;
                }
                return c;
            }

            //aとbを入れ替える
            private void Swap(int a, int b)
            {
                var tmp = this.Array[a];
                this.Array[a] = this.Array[b];
                this.Array[b] = tmp;
            }
        }

        private static bool NextPermutation(int[] array)
        {
            var size = array.Length;
            var ok = false;

            //array[i]<array[i+1]を満たす最大のiを求める
            int i = size - 2;
            for (; 0 <= i; i--)
            {
                if (array[i] < array[i + 1])
                {
                    ok = true;
                    break;
                }
            }

            //全ての要素が降順の場合、NextPermutationは存在しない
            if (ok == false) return false;

            //array[i]<array[j]を満たす最大のjを求める
            int j = size - 1;
            for (; ; j--)
            {
                if (array[i] < array[j]) break;
            }

            //iとjの要素をswapする
            var tmp = array[i];
            array[i] = array[j];
            array[j] = tmp;

            //i以降の要素を反転させる
            Array.Reverse(array, i + 1, size - (i + 1));

            return true;
        }

        //要素数Nを引数として渡し、0～N-1でできた順列をすべて返す
        static List<int[]> GetAllPermutation(int N)
        {
            var res = new List<int[]>();
            var array = Enumerable.Range(0, N).ToArray();
            do
            {
                var copy = new int[N];
                array.CopyTo(copy, 0);
                res.Add(copy);
            } while (NextPermutation(array));

            return res;
        }

        //配列arrayを引数として渡し,辞書順がarray以上の順列をすべて返す
        static List<int[]> GetAllPermutation(int[] array)
        {
            var size = array.Length;
            var res = new List<int[]>();
            do
            {
                var copy = new int[size];
                array.CopyTo(copy, 0);
                res.Add(copy);
            } while (NextPermutation(array));

            return res;
        }
    }
}


public static class Extentions
{
    public static int Int(this object obj)
    {
        return int.Parse(obj.ToString());
    }

    public static long Long(this object obj)
    {
        return long.Parse(obj.ToString());
    }

    public static decimal Decimal(this object obj)
    {
        return decimal.Parse(obj.ToString());
    }

    public static double Double(this object obj)
    {
        return double.Parse(obj.ToString());
    }

    public static T2 GetValueZero<T1, T2>(this Dictionary<T1, T2> d, T1 key) where T2 : struct
    {
        T2 value;
        if (d.TryGetValue(key, out value))
        {
            return value;
        }
        return new T2();
    }
}