using System;
using System.Linq;
using System.Diagnostics;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;

namespace Program
{

    public class Solver
    {
        //validatorつきの想定解
        public void Solve()
        {
            var s = Console.ReadLine().Split(' ');
            var n = int.Parse(s[0]).Validate(x => 1 <= x && x <= 100);
            var X = long.Parse(s[1]).Validate(x => 1 <= x && x <= 1000000000000);
            var a = Console.ReadLine().Split(' ').Validate(x => x.Length == n).Select(int.Parse).ToArray().ValidateArray(x => 1 <= x && x <= 1000000000);
            var dotsum = a.Aggregate(BigInteger.One, (x, y) => x * (BigInteger)y).Validate(x => x <= BigInteger.Pow(10, 100));

            var id = Enumerate(n, x => x);
            //降順ソート
            Array.Sort(id, (l, r) => a[r].CompareTo(a[l]));

            var ans = new char[n];
            for (int i = 0; i < n; i++)
                ans[i] = 'x';

            //大きい方からいくつかは全て試す
            var m = Math.Min(18, n);


            var sum = 0;
            //残りはDPで求める
            for (int i = m; i < n; i++)
                sum += a[id[i]];
            var dp = new bool[sum + 1];
            var prev = new int[sum + 1];
            for (int i = 0; i <= sum; i++)
                prev[i] = -1;
            dp[0] = true;
            for (int i = m, max = 0; i < n; i++)
            {
                var v = a[id[i]];
                for (int j = max; j >= 0; j--)
                {
                    if (!dp[j]) continue;
                    if (dp[j + v]) continue;
                    dp[j + v] = true;
                    prev[j + v] = id[i];
                }
                max += v;
            }


            for (int i = 0; i < 1 << m; i++)
            {
                long v = 0;
                for (int j = 0; j < m; j++)
                    if ((i >> j & 1) == 1) v += a[id[j]];
                var rem = X - v;
                if (rem < 0) continue;
                if (rem > sum) continue;
                if (dp[rem])
                {
                    while (rem > 0)
                    {
                        var p = prev[rem];
                        ans[p] = 'o';
                        rem -= a[p];
                    }
                    for (int j = 0; j < m; j++)
                        if ((i >> j & 1) == 1) ans[id[j]] = 'o';
                    IO.Printer.Out.WriteLine(ans.AsString());
                    return;
                }
            }
            IO.Printer.Out.WriteLine("No");
        }
        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(Scan(), 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
static public class Validator
{
    static public T Validate<T>(this T input, Func<T, bool> f)
    {
        if (!f(input))
            throw new Exception("invalid input");
        return input;
    }
    static public T[] ValidateArray<T>(this T[] input, Func<T, bool> f)
    {
        foreach (var x in input)
            if (!f(x))
                throw new Exception("invalid input");
        return input;
    }
}