#pragma comment(linker,"/STACK:102400000,102400000")

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cstdlib>

 #include<iostream>

 #include<cmath>

 #define maxn 100040

 #define maxm 1000500

 using namespace std;

 typedef long long ll;

 const ll mod=;

 const ll inf=1ll<<;

 ll n,k,ans,size,s[maxn],f[maxn],path[maxn],cr,val[maxn],inv[maxm],ansl,ansr;

 ll head[maxn],cnt,root,pathid[maxn],flag[maxm],mp[maxm],ca;

 bool vis[maxn];

 struct edge{

     ll to,nxt;

 }e[maxn<<];

 void add_edge(ll u,ll v){

     e[cnt].to=v;

     e[cnt].nxt=head[u];

     head[u]=cnt++;

 }

 inline ll read(){

     char k=;char ls;ls=getchar();for(;ls<''||ls>'';k=ls,ls=getchar());

     ll x=;for(;ls>=''&&ls<='';ls=getchar())x=(x<<)+(x<<)+ls-'';

     if(k=='-')x=-x;return x;

 }

 void get_root(ll u,ll fa){//get_root会用到size

     s[u]=;f[u]=;//f是dp数组

     for(ll i=head[u];i!=-;i=e[i].nxt){

         ll v=e[i].to;

         if(v==fa||vis[v]) continue;

         get_root(v,u);

         s[u]+=s[v];

         f[u]=max(f[u],s[v]);

     }

     f[u]=max(f[u],size-s[u]);

     root=f[root]>f[u]?u:root;

 }

 void get_path_size(ll u,ll fa,ll dis){//同时获取size和depth,size是深度，depth是dis的意思

     path[cr]=dis%mod*val[u]%mod;

     pathid[cr]=u;

     cr++;

     s[u]=;

     ll tm=path[cr-]%mod;

     for(ll i=head[u];i!=-;i=e[i].nxt){

         ll v=e[i].to;

         if(v==fa||vis[v]) continue;

         get_path_size(v,u,tm);

         s[u]+=s[v];

     }

 }

 void getans(ll a,ll b){

     if(a>b) swap(a,b);

     if(ansl>a) ansl=a,ansr=b;

     else if(ansl==a&&ansr>b) ansr=b;

 }

 void work(ll u,ll fa){

     vis[u]=true;

     for(ll i=head[u];i!=-;i=e[i].nxt){

         ll v=e[i].to;

         if(v==fa||vis[v]) continue;

         cr=;

         get_path_size(v,u,);

         for(ll j=;j<cr;j++){

             if(path[j]*val[u]%mod==k) getans(pathid[j],u);

             ll tm=k*inv[path[j]*val[u]%mod]%mod;

             if(flag[tm]!=ca) continue;

             getans(mp[tm],pathid[j]);

         }

         for(int j=;j<cr;j++){

             ll tm=path[j];

             if(flag[tm]!=ca||mp[tm]>pathid[j]) flag[tm]=ca,mp[tm]=pathid[j];

         }

     }

     ca++;

     for(ll i=head[u];i!=-;i=e[i].nxt){

         ll v=e[i].to;

         if(vis[v]||v==fa) continue;

         size=s[v],root=;

         get_root(v,u);

         work(root,u);

     }

    // vis[u]=false;

 }

 void init(){

     memset(vis,,sizeof vis);

     memset(head,-,sizeof head);

     //memset(flag,0,sizeof flag);

     ans=cnt=;

     //ca=1;

 }

 ll mod_pow(ll x,ll n,ll p){

     ll res=;

     while(n){

         if(n&) res=res*x%p;

         x=x*x%p;

         n>>=;

     }

     return res;

 }

 int main(){

     ll a,b;

     f[]=inf;inv[]=;

     for(ll i=;i<;i++) inv[i]=mod_pow(i,mod-,mod);

     ca=;

     while(scanf("%lld%lld",&n,&k)!=EOF){

         ca++;

         init();

         for(int i=;i<=n;i++) val[i]=read()%mod;

         for(int i=;i<n-;i++){

             a=read(),b=read();

             add_edge(a,b);

             add_edge(b,a);

         }

         size=n,root=;

         get_root(,-);

         ansl=ansr=inf;

         work(root,-);

         if(ansl==inf) printf("No solution\n");

         else printf("%lld %lld\n",ansl,ansr);

     }

     return ;

 }