#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
using namespace std;
template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
template<class T> istream& operator , (istream& is, T& val){ return is >> val;}
template<class T> ostream& operator << (ostream& os, vector<T>& vec){for(int i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"\n":" ");return os;}

#include <cassert>

int main(){
	long long n,x;
	cin >> n,x;
	vector<long long> a(n);
	cin >> a;

	deque<pair<__int128,__int128>> b(n);
	long long sum = 0;
	for(int i=0; i<n; i++){
		b[i] = {a[i], i};
		sum += a[i];
	}
	sort(b.begin(), b.end());

	int all_size = 20;

	deque<pair<__int128,__int128>> c;
	while(b.size() && c.size()<all_size){
		sum -= b.back().first;
		auto tmp = b.back(); b.pop_back();
		c.push_front(tmp);
	}

	vector<long long> dp1((1<<c.size()));
	for(int i=0; i<dp1.size(); i++){
		long long tmp = 0;
		for(__int128 j=0; j<c.size(); j++){
			if((i>>j)&1) tmp += c[j].first;
		}
		dp1[i] = tmp;
	}

	vector<__int128> dp2(sum+1, 0);
	
	for(int i=0; i<b.size(); i++){
		for(__int128 j=sum-b[i].first; j>=0; j--){
			if(dp2[j] == 0 && j != 0) continue;
			dp2[j+b[i].first] = dp2[j] | (__int128(1)<<(__int128)i);
		}
	}
	


	for(int i=0; i<dp1.size(); i++){
		long long rem = x - dp1[i];
		if(rem < 0) continue;

		long long tmp = 0;
		string ans(n, 'x');
		for(__int128 j=0; j<c.size(); j++){
			if((i>>j)&1){
				ans[c[j].second] = 'o';
				tmp += c[j].first;
			}
		}

		if(rem == 0){
			assert(tmp == x);
			cout << ans << endl;
			return 0;
		}
		if(rem <= sum && dp2[rem] != 0){
			assert(rem + dp1[i] == x);

			for(__int128 j=0; j<b.size(); j++){

				if((dp2[rem]>>j)&(__int128)1){
					ans[b[j].second] = 'o';
					tmp += b[j].first;
				}
			}
			//assert(tmp == x);

			cout << ans << endl;
			return 0;
		}
	}
	cout << "No" << endl;

	return 0;
}