#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back
#define pcnt __builtin_popcount
#define show(x) cout<<#x<<" = "<<x<<endl;
#define maxs(x,y) x = max(x,y)
#define mins(x,y) x = min(x,y)
#define fi first
#define se second
#define rng(a) (a.begin()),(a.end())
#define each(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define sz(x) (int)(x).size()
#define mp make_pair

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vpii;
typedef set<int> si;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pll> vpll;
typedef set<ll> sl;
typedef __int128_t lll;
typedef pair<lll,lll> plll;
typedef vector<lll> vlll;
template<typename T>string join(vector<T>&v)
{stringstream s;FOR(i,0,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename A, size_t N, typename T>void Fill(A (&array)[N], const T&v)
{fill((T*)array,(T*)(array+N),v);}
ll gcd(ll a,ll b){if(a>b)swap(a,b);for(;a>0;b%=a,swap(a,b));return b;}
int modpow(ll a,ll n,int m){if(a==0)return a;ll p=1;for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;return(int)p;}
void dout(double d){printf("%.12f\n",d);}

const int iinf = 1e9;
const ll linf = 1e18;
const int mod = 1e9+7;
const double pi = acos(-1);
const double eps = 1e-10;
int n;
vpll al, ar;
ll x;
vector<bool> ans;
bitset<10000001> bl[101];
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> x;
  ans.resize(n);
  bl[0].set(0);
  int idx = 0;
  FOR(i, 0, n){
    ll a;
    cin >> a;
    if(100000 < a){
      ar.pb(mp(a, i));
    }else{
      bl[idx+1] = bl[idx] | (bl[idx]<<a);
      al.pb(mp(a, i));
      idx++;
    }
  }
  FOR(i, 0, 1<<sz(ar)){
    ll s = x;
    FOR(j, 0, sz(ar)) if(i&(1<<j)) s -= ar[j].fi;
    if(0 <= s && s <= 10000000 && bl[idx][s]){
      FOR(j, 0, sz(ar)) if(i&(1<<j)) ans[ar[j].se] = true;
      FORR(j, idx-1, 0){
        if(al[j].fi <= s && bl[j][s-al[j].fi]){
          ans[al[j].se] = true;
          s -= al[j].fi;
        }
      }
      FOR(j, 0, n) cout << (ans[j] ? 'o' : 'x');
      cout << endl;
      return 0;
    }
  }
  cout << "No" << endl;
  return 0;
}