#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int N;
  int64_t X;
  cin >> N >> X;
  vector<pair<int64_t, int>> P(N);
  for (int i = 0; i < N; i++) {
    int64_t a;
    cin >> a;
    P[i] = make_pair(a, i);
  }
  sort(P.begin(), P.end());
  int64_t sum = 0, bound = 200000;
  vector<int64_t> dp(bound * 2, -1);
  dp[0] = 0;
  int base = 0;
  for (int i = 0; i < N; i++) {
    if (sum + P[i].first > bound) {
      base = i;
      break;
    }
    for (int j = sum; j > -1; j--) {
      if (dp[j] >= 0 && dp[j + P[i].first] == -1) {
        dp[j + P[i].first] = i;
      }
    }
    sum += P[i].first;
  }
  if (sum + P.back().first <= bound) base++;
  vector<char> res(N, 'x');
  for (int b = 0; b < (1 << (N - base)); b++) {
    int64_t t = 0;
    for (int i = 0; i < N - base; i++) {
      if ((b >> i) & 1) t += P[i + base].first;
    }
    if (X - t < 0 || X - t > bound) continue;
    if (dp[X - t] >= 0) {
      for (int i = 0; i < N - base; i++) {
        if ((b >> i) & 1) {
          res[P[i + base].second] = 'o';
        }
      }
      int64_t x = X - t;
      while (x > 0) {
        res[dp[x]] = 'o';
        x -= P[dp[x]].first;
      }
      for (auto &v : res) {
        cout << v;
      }
      cout << '\n';
      return 0;
    }
  }
  cout << "No" << '\n';
  return 0;
}