#include <algorithm>
#include <cmath>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <vector>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
using namespace std;
typedef long long int lli;
const int M = 2000005;
pair<bool, int> dp[M] = {};
int main()
{
    lli n, x;
    lli a[105], b[105];
    vector<lli> big, small, bigm, smallm;
    cin >> n >> x;
    rep(i, n)
    {
        cin >> a[i];
        if (a[i] > 20000) {
            big.push_back(a[i]);
            bigm.push_back(i);
        } else {
            small.push_back(a[i]);
            smallm.push_back(i);
        }
    }
    rep(i, M) dp[i] = make_pair(false, -1);
    if (small.size() > 0) {
        dp[small[0]] = make_pair(true, 0);
    }
    for (int i = 1; i < small.size(); i++) {
        dp[small[i]] = make_pair(true, i);
        rrep(j, M)
        {
            if (dp[j].first && j + small[i] < M && !dp[j + small[i]].first)
                dp[j + small[i]] = make_pair(true, i);
        }
    }
    set<lli> l;
    rep(j, M) if (dp[j].first) l.insert(j);
    map<lli, lli> memo;
    set<lli> s;
    for (lli i = 0; i < (1 << big.size()); i++) {
        lli temp = i;
        lli sum = 0;
        rep(j, big.size())
        {
            if ((temp >> j) & 1)
                sum += big[j];
        }
        //cout << sum << endl;
        memo[sum] = i;
        s.insert(sum);
    }
    s.insert(0);
    l.insert(0);
    for (auto j : s) {
        for (auto i : l) {
            if (j + i == x) {
                //cout << i << endl;
                lli re = memo[j];
                bool flag[105] = {};
                rep(k, big.size())
                {
                    if ((re >> k) & 1) {
                        flag[bigm[k]] = true;
                    }
                }
                lli cnt = dp[i].second;
                if (i > 0) {
                    while (1) {
                        flag[smallm[cnt]] = true;
                        if (i <= 0)
                            break;
                        i -= small[dp[i].second];
                        cnt = dp[i].second;
                        if (cnt < 0)
                            break;
                    }
                }
                cnt = 0;
                rep(k, n)
                {
                    if (flag[k]) {
                        cout << "o";
                    } else
                        cout << "x";
                }
                if (cnt != x) {
                    rep(k, n)
                    {
                        if (!flag[k] && cnt + a[k] == x) {
                            flag[k] = true;break;
                        }
                    }
                }
                rep(k, n)
                {
                    if (flag[k]) {
                        cout << "o";
                    } else
                        cout << "x";
                }
                cout << endl;
                return 0;
            }
        }
    }
    cout << "No" << endl;
}