#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

const int threshold = 35000;
template<class T>
struct DP2 {
  vector<T> dp;
  int h, w;
  DP2(int h_, int w_, T init):h(h_),w(w_),dp(h_*w_, init){}
  T& operator()(int i, int j) { return dp[i*w+j]; }
};

int main(){
  int N;
  ll X;
  cin >> N >> X;
  vector<pair<int,int>> A, B;
  int Asum = 0;
  for(int i=0;i<N;i++){
    int t;
    cin >> t;
    if(t < threshold){
      A.emplace_back(i, t);
      Asum += t;
    } else {
      B.emplace_back(i, t);
    }
  }
  DP2<int> dp(A.size() + 1, Asum + 1, 0);
  DP2<int> pre(A.size() + 1, Asum + 1, -1);
  dp(0, 0) = true;
  for(int i=0;i<A.size();i++){
    for(int sum=0;sum<=Asum;sum++){
      dp(i + 1, sum) = dp(i, sum);
      pre(i + 1, sum) = pre(i, sum);
      if(sum - A[i].second >= 0 && dp(i, sum - A[i].second)){
        dp(i + 1, sum) = 1;
        pre(i + 1, sum) = i;
      }
    }
  }
  for(int m=0;m<1<<B.size();m++){
    ll Bsum = 0;
    for(int i=0;i<B.size();i++)if((m >> i) & 1){
      Bsum += B[i].second;
    }
    if(Bsum > X || X - Bsum > Asum || !dp(A.size(), X - Bsum))continue;
    string res(N, 'x');
    for(int i=0;i<B.size();i++)if((m >> i) & 1){
      res[B[i].first] = 'o';
    }
    ll rem = X - Bsum;
    int k = A.size();
    while(rem > 0){
      int p = pre(k, rem);
      res[A[p].first] = 'o';
      k = p;
      rem -= A[p].second;
    }
    cout << res << endl;
    return 0;
  }
  cout << "No" << endl;
  return 0;
}