#include<cstdio>

 #include<cstring>

 #include<algorithm>

 using namespace std;

 #define INF (1<<30)

 #define MAXN 111111

 struct Edge{

     int v,next;

 }edge[MAXN<<];

 int NE,head[MAXN];

 void addEdge(int u,int v){

     edge[NE].v=v; edge[NE].next=head[u]; head[u]=NE++;

 }

 bool vis[MAXN];

 int mini,cen,size[MAXN];

 void getSize(int u,int fa){

     size[u]=;

     for(int i=head[u]; i!=-; i=edge[i].next){

         int v=edge[i].v;

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

         getSize(v,u);

         size[u]+=size[v];

     }

 }

 void getCen(int u,int fa,int &tot){

     int res=tot-size[u];

     for(int i=head[u]; i!=-; i=edge[i].next){

         int v=edge[i].v;

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

         getCen(v,u,tot);

         res=max(res,size[v]);

     }

     if(res<mini) mini=res,cen=u;

 }

 int getCen(int u){

     getSize(u,u);

     mini=INF;

     getCen(u,u,size[u]);

     return cen;

 }

 long long ine(long long a){

     long long res=,n=;

     while(n){

         if(n&) res*=a,res%=;

         a*=a; a%=;

         n>>=;

     }

     return res;

 }

 int n,k,val[MAXN];

 int ansx,ansy;

 int record[],tn,tmpx[MAXN],tmpy[MAXN],all[MAXN],an;

 void dfs(int u,int fa,long long dist,int &top){

     int v=record[ine(dist)*k%*top%];

     if(v){

         if(u<v){

             if(u<ansx) ansx=u,ansy=v;

             else if(u==ansx && v<ansy) ansy=u,ansy=v;

         }else{

             if(v<ansx) ansx=v,ansy=u;

             else if(v==ansx && u<ansy) ansy=v,ansy=u;

         }

     }

     tmpx[tn]=u; tmpy[tn]=dist; ++tn;

     all[an++]=dist;

     for(int i=head[u]; i!=-; i=edge[i].next){

         int v=edge[i].v;

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

         dfs(v,u,dist*val[v]%,top);

     }

 }

 void conquer(int u){

     an=;

     all[an++]=val[u];

     record[val[u]]=u;

     for(int i=head[u]; i!=-; i=edge[i].next){

         int v=edge[i].v;

         if(vis[v]) continue;

         tn=;

         dfs(v,v,(long long)val[u]*val[v]%,val[u]);

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

             if(record[tmpy[j]]== || record[tmpy[j]]>tmpx[j]) record[tmpy[j]]=tmpx[j];

         }

     }

     for(int i=; i<an; ++i) record[all[i]]=;

 }

 void divide(int u){

     u=getCen(u);

     vis[u]=;

     conquer(u);

     for(int i=head[u]; i!=-; i=edge[i].next){

         int v=edge[i].v;

         if(vis[v]) continue;

         divide(v);

     }

 }

 int main(){

     int a,b;

     while(~scanf("%d%d",&n,&k)){

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

             scanf("%d",val+i);

         }

         NE=;

         memset(head,-,sizeof(head));

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

             scanf("%d%d",&a,&b);

             addEdge(a,b);

             addEdge(b,a);

         }

         memset(vis,,sizeof(vis));

         ansx=ansy=INF;

         divide();

         if(ansx==INF) puts("No solution");

         else printf("%d %d\n",ansx,ansy);

     }

     return ;

 }