#include<algorithm>
#include<iostream>
#include<string.h>
#include<stdio.h>
#pragma comment(linker,"/STACK:102400000,102400000")
using namespace std;
const int INF=0x3f3f3f3f;
const int maxn=100010;
const int mod=1e6+3;
typedef long long ll;
ll inv[mod+10];
int val[maxn],ms[maxn],son[maxn],vis[maxn],cnt,kv;
int mp[mod+10],use[mod+10],ptr,pos,ans1,ans2;
struct node
{
    int v;
    node *next;
} ed[maxn<<1],*head[maxn];
void adde(int u,int v)
{
    ed[cnt].v=v;
    ed[cnt].next=head[u];
    head[u]=&ed[cnt++];
}
void dfs(int fa,int u)
{
    son[u]=1;
    ms[u]=0;
    for(node *p=head[u];p!=NULL;p=p->next)
    {
        if(p->v==fa||vis[p->v])
            continue;
        dfs(u,p->v);
        son[u]+=son[p->v];
        ms[u]=max(ms[u],son[p->v]);
    }
}
void findroot(int fa,int u,int all)
{
    ms[u]=max(ms[u],all-son[u]);
    if(ms[u]<ms[pos])
        pos=u;
    for(node *p=head[u];p!=NULL;p=p->next)
    {
        if(p->v==fa||vis[p->v])
            continue;
        findroot(u,p->v,all);
    }
}
void getroot(int u)
{
    dfs(-1,u);
    pos=u;
    findroot(-1,u,son[u]);
}
void cal(int fa,int u,int mc)//计算答案
{
    mc=(ll)mc*val[u]%mod;
    int op=(ll)kv*inv[mc]%mod,a,b;
    if(mp[op])
    {
        a=u,b=mp[op];
        if(a>b)
            swap(a,b);
        if(a<ans1)
            ans1=a,ans2=b;
        else if(a==ans1&&b<ans2)
            ans2=b;
    }
    for(node *p=head[u];p!=NULL;p=p->next)
    {
        if(p->v==fa||vis[p->v])
            continue;
        cal(u,p->v,mc);
    }
}
void update(int fa,int u,int mc)//更新hash表
{
    mc=(ll)mc*val[u]%mod;
    if(!mp[mc])
        use[ptr++]=mc,mp[mc]=u;
    else
        mp[mc]=min(mp[mc],u);
    for(node *p=head[u];p!=NULL;p=p->next)
    {
        if(p->v==fa||vis[p->v])
            continue;
        update(u,p->v,mc);
    }
}
void solve(int u)//每次处理一颗子树
{
    int root,i;
    getroot(u);
    root=pos;
    mp[val[root]]=root;
    vis[root]=1,ptr=0;
    for(node *p=head[root];p!=NULL;p=p->next)
    {
        if(vis[p->v])
            continue;
        cal(root,p->v,1);//计算子树路径
        update(root,p->v,val[root]);
    }
    for(i=0;i<ptr;i++)
        mp[use[i]]=0;
    mp[val[root]]=0;
    for(node *p=head[root];p!=NULL;p=p->next)
    {
        if(vis[p->v])
            continue;
        solve(p->v);
    }
}
int main()
{
    int n,i,u,v;
    inv[1]=1;
    for(i=2;i<mod;i++)//预处理逆元
        inv[i]=(mod-mod/i)*inv[mod%i]%mod;
    while(~scanf("%d%d",&n,&kv))
    {
        for(i=1;i<=n;i++)
            scanf("%d",&val[i]);
        memset(head,0,sizeof head);
        memset(vis,0,sizeof vis);
        cnt=0;
        for(i=1;i<n;i++)
        {
            scanf("%d%d",&u,&v);
            adde(u,v);
            adde(v,u);
        }
        ans1=ans2=INF;
        solve(1);
        if(ans1!=INF)
            printf("%d %d\n",ans1,ans2);
        else
            printf("No solution\n");
    }
    return 0;
}