#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <sstream>
#include <string>
#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define var auto
#define mod 1000000007
#define inf 2147483647
#define mp make_pair
#define pb push_back
typedef long long ll;
using namespace std;

template <typename T>
inline void output(T a, int p) {
    if(p){
        cout << fixed << setprecision(p)  << a << "\n";
    }
    else{
        cout << a << "\n";
    }
}
// end of template

int main() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    // source code
    
    int N; // N <= 100
    ll X;
    cin >> N >> X;
    
    vector<pair<ll, int>> A(N);
    rep(i, N){
        cin >> A[i].first;
        A[i].second = i;
    }
    
    string ret = "";
    rep(i, N){
        ret += 'x';
    }
    
    sort(A.begin(), A.end());
    
    ll sum = 0;
    int cnt = 0;
    
    while (cnt < N) {
        if (sum + A[cnt].first > 200000) {
            break;
        }
        sum += A[cnt].first;
        cnt++;
    }
    
    
    vector<ll> dp(sum + 1, -1);
    dp[0] = 0;
    rep(i, cnt){
        for (int j = (int)sum; j >= 0; j--) {
            if (dp[j] >= 0 && dp[j + A[i].first] == -1) {
                dp[j + A[i].first] = i;
            }
        }
        
    }
    
    bool exist = false;
    
    rep(i, 1 << (N - cnt)){
        ll tmp = 0;
        rep(j, N - cnt){
            if (i & (1 << j)) tmp += A[cnt + j].first;
        }
        if (X - tmp < 0 || X - tmp > sum) continue;
        if (dp[X - tmp] >= 0) {
            rep(j, N - cnt){
                if (i & (1 << j)) ret[A[cnt + j].second] = 'o';
            }
            ll left = X - tmp;
            while (left) {
                ret[A[dp[left]].second] = 'o';
                left -= A[dp[left]].first;
            }
            exist = true;
            break;
        }
    }
    
    if (exist) {
        cout << ret << endl;
    }
    else{
        output("No", 0);
    }
    
    
    
    
    return 0;
}