import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


enum LIM = 10^^4;

int N;
long X;
long[] A;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      X = readLong();
      A = new long[N];
      foreach (i; 0 .. N) {
        A[i] = readLong();
      }
      
      const lim = LIM * N + 1;
      auto dp = new int[lim];
      dp[] = -1;
      dp[0] = -2;
      foreach (i; 0 .. N) {
        if (A[i] <= LIM) {
          foreach_reverse (x; A[i] .. lim) {
            if (dp[cast(int)(x - A[i])] != -1) {
              dp[cast(int)(x)] = i;
            }
          }
        }
      }
      
      int[] bigIs;
      foreach (i; 0 .. N) {
        if (A[i] > LIM) {
          bigIs ~= i;
        }
      }
if(bigIs.length>25)for(;;){}
      assert(bigIs.length <= 25);
      
      string ans = "No";
      foreach (p; 0 .. 1 << bigIs.length) {
        long x = X;
        foreach (j, i; bigIs) {
          if ((p >> j) & 1) {
            x -= A[i];
          }
        }
        if (0 <= x && x < lim && dp[cast(int)(x)] != -1) {
          auto used = new bool[N];
          foreach (j, i; bigIs) {
            if ((p >> j) & 1) {
              used[i] = true;
            }
          }
          for (; x > 0; ) {
            const i = dp[cast(int)(x)];
            used[i] = true;
            x -= A[i];
          }
          ans = used.map!(b => (b ? 'o' : 'x')).to!string;
          goto found;
        }
      }
     found:
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}