#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
using namespace std;
typedef long long int ll;
typedef pair<ll, int> P;
int n; ll x;
vector<ll> s1;
ll a[101];
vector<int> ind1, ind2;
ll sum1;
ll s2;
ll ans1, ans2;
bool used2[25];
bool used[25];
void dfs(int i){
	if(ans1 || ans2) return;
	if(i==ind2.size()){
		if(x-s2<0 || x-s2>sum1) return;
		int j=lower_bound(s1.begin(), s1.end(), x-s2)-s1.begin();
		if(s1[j]==x-s2){
			ans1=s1[j], ans2=s2;
			for(int j=0; j<ind2.size(); j++) used2[j]=used[j];
		}
      return;
	}
	dfs(i+1);
	used[i]=1;
	s2+=a[ind2[i]];
	dfs(i+1);
	used[i]=0;
	s2-=a[ind2[i]];
}
int main()
{
	cin>>n>>x;
	for(int i=0; i<n; i++){
		cin>>a[i];
		if(a[i]<=10000) ind1.push_back(i), sum1+=a[i];
		else ind2.push_back(i);
	}
	bool dp[101][1000001];
	fill(dp[0], dp[0]+sum1+1, 0);
	dp[0][0]=1;
	for(int i=1; i<=ind1.size(); i++){
		int i1=ind1[i-1];
		for(int j=0; j<=sum1; j++) dp[i][j]=dp[i-1][j];
		for(int j=a[i1]; j<=sum1; j++) dp[i][j]|=dp[i-1][j-a[i1]];
	}
	for(int i=0; i<=sum1; i++) if(dp[ind1.size()][i]) s1.push_back(i);
	dfs(0);
	if(ans1==0 && ans2==0){
		cout<<"No"<<endl;
		return 0;
	}
	char ans[101];
	int i1=ind1.size();
	while(i1){
		if(dp[i1-1][ans1]){
			ans[ind1[i1-1]]='x';
		}else{
			ans1-=a[ind1[i1-1]];
			ans[ind1[i1-1]]='o';
		}
		i1--;
	}
	for(int i=0; i<ind2.size(); i++){
		if(used2[i]) ans[ind2[i]]='o';
		else ans[ind2[i]]='x';
	}
	for(int i=0; i<n; i++) cout<<ans[i];
	cout<<endl;
	return 0;
}