answer.code:14:23: error: expected initializer before ‘，a’
   14 | int n, m, d[N], vis[N]，a[N]; array<int, 2> E[N]; vector<int> e[N];
      |                       ^~~
answer.code: In function ‘int main()’:
answer.code:19:1: error: ‘a’ was not declared in this scope
   19 | a[i]=read();
      | ^
answer.code:32:29: error: ‘vis’ was not declared in this scope
   32 |         for (auto v : e[u]) vis[v] = u;
      |                             ^~~
answer.code:34:17: error: ‘vis’ was not declared in this scope
   34 |             if (vis[w] == u) (ans+=a[w]*a[u]%mod*a[v])%=mod;
      |                 ^~~
answer.code:34:36: error: ‘a’ was not declared in this scope
   34 |             if (vis[w] == u) (ans+=a[w]*a[u]%mod*a[v])%=mod;
      |                                    ^