Problem:
m 頂点の完全グラフがある．最初，完全グラフの辺には色は塗られていない．すぬけ君は，各 i(1 ≤ i ≤ n) について次の操作を行った: 完全グラフから ai 個の頂点を選び，選ばれた頂点同士を結ぶ辺すべてを色 i でぬる．複数個の色が塗られた辺はなかった．m として考えられる最小値を求めよ．

Constraints

1 ≤ n ≤ 5

2 ≤ ai ≤ 109

Input

n
a1
. . .
an

Output

m の最小値を一行に出力せよ．

Sample Input 1

2
3
3

Sample Output 1

5

たとえば，頂点1, 2, 3, 4, 5 からなるグラフがあった場合，次のように色を塗ることができる．

頂点1, 2, 3 を選びその間を結ぶ辺を色1 でぬる．

頂点1, 4, 5 を選びその間を結ぶ辺を色2 でぬる．

Sample Input 2

5
2
3
4
5
6

Sample Output 2

12

Solution in C# (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
//using System.Numerics;
//using Point = System.Numerics.Complex;
//using Number = System.Int64;
namespace Program
{
    public class Solver
    {

        public void Solve()
        {
            var n = sc.Integer();
            var a = new int[5];
            for (int i = 0; i < n; i++)
                a[i] = sc.Integer();
            n = 5;
            var ans = 0L;
            for (int i = 0; i < 5; i++)
            {
                ans += Math.Max(0, a[i] - 4);
                a[i] = Math.Min(a[i], 4);
            }
            Array.Sort(a);
            var g = new long[32];
            for (int i = 0; i < 32; i++)
                for (int j = 0; j < 32; j++)
                {
                    var k = i & j;
                    var cnt = 0;
                    while (k > 0) { cnt += k % 2; k /= 2; }
                    if (cnt >= 2) g[i] |= 1L << j;
                }
            var pass = new bool[32];
            for (int i = 0; i < 5; i++)
                pass[1 << i] = true;
            Func<int, long, int> dfs = null;
            dfs = (cur, mask) =>
              {
                  if (cur == 0) return a.Sum();
                  var ret = dfs(cur - 1, mask);
                  if (!pass[cur] && (mask & g[cur]) == 0)
                  {
                      for (int i = 0; i < 5; i++)
                          if ((cur >> i & 1) == 1) a[i]--;
                      var ok = true;
                      for (int i = 0; i < 5; i++)
                          ok &= a[i] >= 0;
                      if (ok) ret = Math.Min(ret, dfs(cur, mask | 1L << cur) + 1);
                      for (int i = 0; i < 5; i++)
                          if ((cur >> i & 1) == 1) a[i]++;

                  }
                  return ret;
              };
            IO.Printer.Out.WriteLine(ans + dfs(31, 0));
        }

        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    //static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    //static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer: StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion