#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;++i)
using namespace std;
using ll=long long ;

int n;
ll x,a[110];
map<ll,ll> dp[110];

int main(void){
	cin >> n >> x;
	rep(i,n) cin >> a[i];

	dp[0][0]=-1;
	rep(i,n){
		for(auto &it:dp[i]){
			ll cur=it.first;
			dp[i+1][cur]=cur;
			dp[i+1][cur+a[i]]=cur;
		}		
	}

	if(dp[n].find(x)!=dp[n].end()){
		string ans="";
		ll cur=x;
		for(int i=n;i>0;--i){
			if(cur!=dp[i][cur]){
				ans+="o";
			}else{
				ans+="x";
			}
			cur=dp[i][cur];
		}
		reverse(ans.begin(),ans.end());
		cout << ans << endl;
	}else{
		puts("No");
	}
	return 0;
}