#include<algorithm>

 #include<cstdio>

 #include<cmath>

 #include<cstring>

 #include<iostream>

 #define ll long long

 const ll Mod=;

 int tot,go[],first[],next[],a[],d,n;

 ll f[];

 int read(){

     int t=,f=;char ch=getchar();

     while (ch<''||ch>''){if (ch=='-') f=-;ch=getchar();}

     while (''<=ch&&ch<=''){t=t*+ch-'';ch=getchar();}

     return t*f;

 }

 void insert(int x,int y){

     tot++;

     go[tot]=y;

     next[tot]=first[x];

     first[x]=tot;

 }

 void add(int x,int y){

     insert(x,y);insert(y,x);

 }

 void dfs(int x,int fa,int fi){

     f[x]=;

     for (int i=first[x];i;i=next[i]){

         int pur=go[i];

         if (pur==fa) continue;

         if (a[pur]>a[fi]) continue;

         if (a[fi]-d>a[pur]) continue;

         if (a[fi]==a[pur]&&fi>pur) continue;

         dfs(pur,x,fi);

         f[x]*=(1LL+f[pur]);

         f[x]%=Mod;

     }

 }

 int main(){

     d=read();n=read();

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

      a[i]=read();

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

         int x=read(),y=read();

         add(x,y);

     }

     ll ans=;

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

      for (int j=;j<=n;j++) f[j]=;

      dfs(i,,i);

      ans=(ans+f[i])%Mod;

     }

     printf("%I64d\n",ans);

 }