1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 #include<algorithm>
 5 #include<cstdlib>
 6 #include<cmath>
 7 #include<vector>
 8 #include<queue>
 9 #include<map>
10 #include<set>
11 #define eps 10e-13
12
13 using namespace std;
14
15 typedef long long ll;
16
17 int b[25],v[25],n,a,c,ans;
18 bool vis[25];
19
20 void dfs(int cur)
21 {
22     if(cur==-1)
23     {
24         int t = a;
25         for(int i=0;i<c;i++)
26             t%=v[i];
27         if(t==0) ans = min(ans,c);
28         return;
29     }
30     vis[cur] = true;
31     v[c++] = b[cur];
32     dfs(cur-1);
33     vis[cur] = false;
34     c--;
35     dfs(cur-1);
36 }
37
38 int main()
39 {
40     int T;
41     scanf("%d",&T);
42     while(T--)
43     {
44         scanf("%d%d",&n,&a);
45         for(int i=0;i<n;i++)
46             scanf("%d",&b[i]);
47         sort(b,b+n);
48         c = 0;
49         memset(vis,0,sizeof(vis));
50         ans = 30;
51         dfs(n-1);
52         printf("%d\n",ans==30?-1:ans);
53     }
54     return 0;
55 }

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 #include<algorithm>
 5 #include<cstdlib>
 6 #include<cmath>
 7 #include<vector>
 8 #include<queue>
 9 #include<map>
10 #include<set>
11 #define eps 10e-13
12
13 using namespace std;
14
15 typedef long long ll;
16
17 int b[30],v[30],n,a,c,ans;
18
19 void dfs(int cur,int x,int len)
20 {
21     if(x==0) ans = min(ans,len);
22     if(cur==-1) return;
23     dfs(cur-1,x,len);
24     dfs(cur-1,x%b[cur],len+1);
25 }
26
27 int main()
28 {
29     int T;
30     scanf("%d",&T);
31     while(T--)
32     {
33         scanf("%d%d",&n,&a);
34         for(int i=0;i<n;i++)
35             scanf("%d",&b[i]);
36         sort(b,b+n);
37         c = 0;
38         ans = 30;
39         dfs(n-1,a,0);
40         if(ans<30) printf("%d\n",ans);
41         else printf("-1\n");
42     }
43     return 0;
44 }