HDU 3486

#include <cstdio>
#include <cstring>
const int N = 1111;
char buf[N], op[N];
int lch[N], rch[N];
int h[N];
int build(char s[], int x, int y, int lch[], int rch[], char op[], int &nc) {
	int i, u, c1, c2;
	int p = 0;
	c1 = c2 = -1;
	if (x == y)
		return -1;
	if (y - x == 1) {
		u = ++nc;
		lch[u] = rch[u] = 0;
		op[u] = s[x];
		return u;
	}
	for (i = x; i < y; ++i) {
		if (s[i] == '(')
			++p;
		if (s[i] == ')')
			--p;
		if (s[i] == '+' && !p)
			c1 = i;
		if (s[i] == '-' && !p)
			c1 = i;
		if (s[i] == '*' && !p)
			c2 = i;
		//putchar(s[i]);
	}
	if (c1 < 0)
		c1 = c2;
	if (c1 < 0)
		return build(s, x + 1, y - 1, lch, rch, op, nc);
	u = ++nc;
	lch[u] = build(s, x, c1, lch, rch, op, nc);
	rch[u] = build(s, c1 + 1, y, lch, rch, op, nc);
	op[u] = s[c1];
	return u;
}
int dfs(int u, int lch[], int rch[], char op[]) {
	if (!lch[u]) {
		char ch = op[u];
		if (ch >= 'a' && ch <= 'z')
			return h[ch - 'a'];
		return 0;
	}
	if (op[u] == '+')
		return dfs(lch[u], lch, rch, op) + dfs(rch[u], lch, rch, op);
	if (op[u] == '-')
		return dfs(lch[u], lch, rch, op) - dfs(rch[u], lch, rch, op);
	return dfs(lch[u], lch, rch, op) * dfs(rch[u], lch, rch, op);
}
int v[N], n, size, m;
int ch[15];
bool used[15];
bool solve(int dep) {
	if (dep == size) {
		return dfs(1, lch, rch, op)==m;
	}
	for (int i = 0; i < n; ++i) {
		if(used[i]) continue;
		h[ch[dep]] = v[i];
		used[i]=true;
		if (solve(dep + 1))
			return true;
		used[i]=false;
	}
	return false;
}
int main() {
	int i, len, nc;
	while (~scanf("%d%d", &n, &v[0]) && (n | v[0])) {
		for (i = 1; i < n; ++i)
			scanf("%d", v + i);

		nc = 0;
		scanf("%d", &m);
		scanf("%s", buf);
		len = strlen(buf);
		for (i = 0, size = 0; i < len; ++i)
			if (buf[i] >= 'a' && buf[i] <= 'z')
				ch[size++] = buf[i] - 'a';
		build(buf, 0, len, lch, rch, op, nc);
		bool flag = solve(0);
		if (flag)
			puts("YES");
		else
			puts("NO");
	}
	return 0;
}