# include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <ll, ll> P; 
 
const int N = 310;
const int M = 50010;
ll n, t, les, mor;
ll dp[N * M];
P p[N];
bool vis[N];

int main()
{
	scanf("%lld%lld", &n, &t);
	for (int i = 0; i < n; i++) scanf("%lld", &p[i].first), p[i].second = i;
	sort(p, p + n);
	les = 0;
	while (les < n && p[les].first < M) les++;
	mor = n - les;
	memset(dp, -1, sizeof(dp));
	dp[0] = 0;
	for (int i = 0; i < les; i++)
	{
		for (int j = p[i].first * (i + 1); j >= p[i].first; j--)
		{
			if (dp[j] == -1) dp[j] = (dp[j - p[i].first] != -1) ? i : -1;
		}
	}
	for (int S = 0, sum; S < (1 << mor); S++)
	{
		sum = t;
		for (int i = 0; i < mor; i++) if (S & (1 << i)) sum -= p[i + les].first;
		if (sum >= 0 && sum < n * M)
		{
			if (dp[sum] == -1) continue;
			for (int i = 0; i < mor; i++) if (S & (1 << i)) vis[p[i + les].second] = true;
			while (sum)
			{
				vis[p[dp[sum]].second] = true;
				sum -= p[dp[sum]].first;
			}
			for (int i = 0; i < n; i++) printf(vis[i] ? "o" : "x");
			printf("\n");
			exit(0);
		}
	}
	printf("No\n");
    return 0;
}