#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

bool solve(const vector<int>& a, int x, vector<bool>& ans)
{
    int n = a.size();
    vector<int> dp(x+1, -1);
    dp[0] = 0;
    for(int i=0; i<n; ++i){
        for(int j=x; j>=a[i]; --j){
            if(dp[j] == -1 && dp[j-a[i]] != -1)
                dp[j] = i;
        }
    }
    if(dp[x] == -1)
        return false;

    ans.assign(n, false);
    int i = x;
    while(i != 0){
        ans[dp[i]] = true;
        i -= a[dp[i]];
    }
    return true;
}

int main()
{
    int n;
    long long x;
    cin >> n >> x;

    vector<int> a, b;
    vector<int> aIndex, bIndex;
    for(int i=0; i<n; ++i){
        int c;
        cin >> c;
        if(c < 20000){
            a.push_back(c);
            aIndex.push_back(i);
        }
        else{
            b.push_back(c);
            bIndex.push_back(i);
        }
    }
    
    int aSum = accumulate(a.begin(), a.end(), 0);
    int m = b.size();
    for(int i=0; i<(1<<m); ++i){
        bitset<32> bs(i);
        long long y = x;
        for(int j=0; j<m; ++j){
            if(bs[j])
                y -= b[j];
        }

        if(0 <= y && y <= aSum){
            vector<bool> used;
            if(solve(a, (int)y, used)){
                string ans(n, 'x');
                for(int j=0; j<m; ++j){
                    if(bs[j])
                        ans[bIndex[j]] = 'o';
                }
                for(unsigned j=0; j<used.size(); ++j){
                    if(used[j])
                        ans[aIndex[j]] = 'o';
                }
                cout << ans << endl;
                return 0;
            }
        }
    }

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