#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <bitset>
#include <cstdlib>
#include <utility>
using namespace std;

const int lim = 100006;
const int sz = lim * 100 + 6;

typedef long long LL;
typedef bitset<sz> bsz;
typedef pair<int,int> pii;
typedef pair<LL,int> pli;

int n;
vector<pii> big, small;
vector<bsz> dp;

void dfs(int k, int S, LL rest){
	if(rest < 0){ return; }
	if(k == (int)big.size()){
		if(rest >= sz || !dp.back()[rest]){ return; }
		string ans(n, 'x');
		for(int i = big.size(); i--; )
		if(S >> i & 1){
			ans[big[i].second] = 'o';
		}
		for(int p = small.size() - 1; p >= 0; --p){
			if(!dp[p][rest]){
				ans[small[p].second] = 'o';
				rest -= small[p].first;
			}
		}
		cout << ans << '\n';
		exit(0);
	}
	else{
		dfs(k + 1, S, rest);
		dfs(k + 1, S | 1 << k, rest - big[k].first);
	}
}

int main(){
	LL x;
	
	cin >> n >> x;
	for(int i = 0; i < n; ++i){
		int a;
		cin >> a;
		(a < lim ? small : big).emplace_back(a, i);
	}
	
	dp.resize(small.size() + 1);
	dp[0].set(0);
	for(size_t i = 0; i < small.size(); ++i){
		dp[i + 1] = dp[i] | dp[i] << small[i].first;
	}
	
	dfs(0, 0, x);
	
	cout << "No\n";
}