# include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <ll, ll> pii; 

const int MAXN = 111;
const int MAX = 50000;
pii A[MAXN];
int dp[MAXN*MAX];
bool use[MAXN];

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    ll X;
    cin >> N >> X;
    for (int i = 0; i < N; i++) {
        cin >> A[i].first;
        A[i].second = i;
    }
    sort(A, A+N);
    int cnt = 0;
    memset(dp, -1, sizeof(dp));
    dp[0] = 0;
    for (; cnt < N && A[cnt].first < MAX; cnt++) {}
    for (int i = 0; i < cnt; i++) {
        for (int j = (i+1)*A[i].first; j >= A[i].first; j--) {
            if (dp[j] != -1) continue;
            if (dp[j-A[i].first] == -1) continue;
            dp[j] = i;
        }
    }
    int rest = N-cnt;
    for (int s = 0; s < 1<<rest; s++) {
        ll sum = 0;
        for (int i = 0; i < rest; i++) {
            if ((s>>i)&1) sum += A[cnt+i].first;
        }
        ll tar = X - sum;
        if (0 <= tar && tar < MAXN * MAX && dp[tar] != -1)
		{
            for (int i = 0; i < rest; i++)
			{
                if ((s>>i)&1) use[A[i+cnt].second] = true;
            }
            ll now;
			now = tar;
            while (now != 0) 
            {
                use[A[dp[now]].second] = true;
                now -= A[dp[now]].first;
            }
            for (int i = 0; i < N; i++)
			{
                if (use[i]) cout << "o";
                else cout << "x";
            }
            cout << endl;
            return 0;
        }
    }
    cout << "No\n";
    return 0;
}