1 #include<iostream>
 2 #include<cstring>
 3 using namespace std;
 4 int f[2000],g[1<<17],t[20],n;
 5 void dp(int sum,int x)
 6 {
 7     if (sum&1) return;
 8     memset(f,0,sizeof(f)),f[0]=1;
 9     for (int i=0;i<n;i++)  if (x&1<<i) for (int j=sum;j>=t[i];j--) if (f[j-t[i]]) f[j]=1;
10     if (f[sum>>1]) g[x]=1;
11 }
12 int ans;
13 void dfs(int k,int x1,int sum1,int x2,int sum2)
14 {
15     if (k==n)
16     {
17         if (g[x1]&&g[x2]) ans=max(ans,sum1*sum2/4);
18         return;
19     }
20     dfs(k+1,x1,sum1,x2,sum2),dfs(k+1,x1+(1<<k),sum1+t[k],x2,sum2),dfs(k+1,x1,sum1,x2+(1<<k),sum2+t[k]);
21 }
22 int main ()
23 {
24     cin>>n;
25     for (int i=0;i<n;i++)
26       cin>>t[i];
27     int sum=0;
28     for (int i=1;i<=(1<<n)-1;i++)
29     {
30         sum=0;
31         for (int j=0;j<n;j++) if (i&1<<j) sum+=t[j];
32         dp(sum,i);
33     }
34     dfs(0,0,0,0,0);
35     if (ans)
36     cout<<ans;
37     else
38      cout<<"No Solution";
39 }