#include <bits/stdc++.h>

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()

using namespace std;

typedef long long ll;

int dp[4096000];

string solve() {
  int N; ll X;
  cin >> N >> X;
  memset(dp, -1, sizeof(dp));
  dp[0] = 0;
  vector<int> A(N);
  vector<pair<int,ll>> B;
  REP(i,N) {
    cin >> A[i];
    if (A[i] < 100000) {
      for (int j = 2010000; j >= 0; --j)
        if (dp[j] >= 0 && dp[j+A[i]] == -1) dp[j+A[i]] = i;
    }
    else B.emplace_back(i, A[i]);
  }
  int M = B.size();
  REP(bit,1<<M) {
    ll sum = 0;
    REP(i,M) if ((bit >> i) & 1) sum += B[i].second;
    if (0 <= X - sum && X - sum < 4096000 && dp[X-sum] >= 0) {
      string res(N, 'x');
      REP(i,M) if ((bit >> i) & 1) res[B[i].first] = 'o';
      for (int val = X - sum; val > 0; val -= A[dp[val]])
        res[dp[val]] = 'o';
      return res;
    }
  }
  return "No";
}

int main() { cout << solve() << endl; }