#include <iostream>
#include <vector>
#include <map>
#include <utility>
#include <tuple>

using namespace std;

#define rep(i,x) for(int i=0;i<x;++i)

template<class T,class U>ostream&operator<<(ostream&os,const pair<T,U>p){os<<"("<<p.first<<", "<<p.second<<")";return os;}

using int64 = long long;

using data = pair<int64, int>;

map<int64, data> dp;

int64 N, X;
int A[105];

string ans = "";

int main()
{
    cin >> N >> X;

    rep(i, N) cin >> A[i], ans += "x";

    dp[0] = data(-1, -1);

    rep(i, N) {
        int len = dp.size();

        vector<pair<int64, data>> hoge;

        for (auto it = begin(dp); it != end(dp); ++it) {
            hoge.emplace_back(it->first, it->second);
        }

        //cout << "debug:\n";
        rep(j, hoge.size()) {
            int64 v = hoge[j].first;
            data info = hoge[j].second;

            if (dp.find(v + A[i]) == end(dp)) {
                dp[v + A[i]] = data(v, i);
            }
        }
        //cout << endl;
        //break;
    }

    if (dp.find(X) == end(dp)) {
        cout << "No" << endl;
        return 0;
    }

    data cur = dp[X];
    while (cur.first >= 0) {
        ans[cur.second] = 'o';
        cur = dp[cur.first];
    }

    cout << ans << endl;
}