// yukicoder: No.332 数列をプレゼントに
// 2019.7.8 bal4u

#include <stdio.h>
#include <stdlib.h>

typedef long long ll;

#if 1
#define gc() getchar_unlocked()
#define pc(c) putchar_unlocked(c)
#else
#define gc() getchar()
#define pc(c) putchar(c)
#endif

ll in() {   // 非負整数の入力
	ll n = 0; int c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

void outs(char *s) { while (*s) pc(*s++); pc('\n'); }
void outc(int f, char c) { while (f--) pc(c); pc('\n'); }

#define LIM 100000

typedef struct { int v, id; } T;
T a[105], b[105]; int fa, fb; int N; ll X;
char f[105];
int dp[80*LIM];

int cmp(const void *a, const void *b) { return ((T *)a)->v - ((T *)b)->v; }

void final(int p, int q) {
	int i;
//	printf("final: p=%d, q=%x\n", p, q); fflush(stdout);
	while (p) {
//		printf("p=%d, prev=%d, id=%d\n", p, dp[p] >> 7, (dp[p] & 127)-1);
		f[(dp[p] & 127)-1] = 1;
		p = dp[p] >> 7;
	}
	for (i = 0; q; i++) {
		if (q & 1) {
			f[b[i].id] = 1;
//			printf("q=%d, x=%d, id=%d\n", i, b[i].id);
		}
		q >>= 1;
	}
	for (i = 0; i < N; i++) pc(f[i]? 'o': 'x');
	pc('\n');
	exit(0);
}

int main()
{
	int i, j, x, ma;
	ll s;
	
	N = (int)in(), X = in(), s = 0, fa = 1, fb = 0;
	for (i = 0; i < N; i++) {
		x = (int)in(), s += x;
		if (x <= LIM) a[++fa].id = i, a[fa].v = x;
		else b[fb].id = i, b[fb++].v = x;
	}
	if (s == X) { outc(N, 'o'); return 0; }

	qsort(a+2, fa-1, sizeof(T), cmp);
	
//	printf("fa=%d, fb=%d\n", fa, fb);
	dp[0] = 1, ma = 0;
	for (i = 2; i <= fa; i++) {
		for (j = ma; j >= 0; j--) {
			if (dp[j] && !dp[j+a[i].v]) dp[j+a[i].v] = (j << 7) | (a[i].id+1);
		}
		ma += a[i].v;
	}
//	printf("ma=%d\n", ma);
	if (X <= ma && dp[X]) final(X, 0);
	
	i = 1 << fb; while (--i) {
		s = 0, x = i;
		for (j = 0; x; j++) {
			if (x & 1) s += b[j].v;
			x >>= 1;
		}
		if (s <= X && X-s <= ma && dp[X-s]) final(X-s, i);
	}
	outs("No");
	return 0;
}