#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(a, b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define pb push_back
#define show(x) cout <<#x<<" = "<<(x)<<endl
#define spair(p) cout <<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout <<" "<<kbrni;cout<<endl

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 100005;

int dp[1000001];
int last[1000001];
map<ll,int> mp;
bool flag[101];

int main()
{
    int n;
    ll x;
    cin >> n >> x;
    vector<int> u;
    vector<int> v;
    vector<int> id1,id2;
    rep(i,n){
        int a;
        cin >> a;
        if(a > 10001){
            v.pb(a);
            id1.pb(i);
        }else{
            u.pb(a);
            id2.pb(i);
        }
    }
    dp[0] = 1;
    rep(i,u.size()){
        for(int j=1000001;j>=0;j--){
            if(j+u[i] <= 1000000 && dp[j] >= 1){
                dp[j+u[i]]++;
                last[j+u[i]] = i;
            }
        }
    }
    vector<int> vec;
    rep(i,1000001){
        if(dp[i] > 0){
            vec.pb(i);
        }
    }
    vector<ll> vec2;
    rep(i,(1 << (int)(v.size()))){
        ll sm = 0;
        rep(j,v.size()){
            if(i & (1 << j)){
                sm += v[j];
            }
        }
        vec2.pb(sm);
        mp[sm] = i;
    }
    sort(all(vec2));
    vec2.erase(unique(all(vec2)),vec2.end());
    rep(i,vec.size()){
        int cnt = upper_bound(all(vec2),x-vec[i])-lower_bound(all(vec2),x-vec[i]);
        if(cnt >= 1){
            int bf = vec[i];
            vector<int> use;
            while(bf){
                use.pb(last[bf]);
                bf -= u[last[bf]];
            }
            rep(j,use.size()){
                flag[id2[use[j]]] = true;
            }
            use.clear();
            bf = mp[x-vec[i]];
            rep(j,25){
                if(bf & (1 << j)){
                    use.pb(j);
                }
            }
            rep(j,use.size()){
                flag[id1[use[j]]] = true;
            }
            rep(j,n){
                if(flag[j]){
                    cout << 'o';
                }else{
                    cout << 'x';
                }
            }
            cout << endl;
            return 0;
        }
    }
    cout << "No\n";
    return 0;
}