#include<cstdio>

 #include<cmath>

 #include<algorithm>

 using namespace std;

 const int maxn=;

 int n,m,x,y,ans=,tot=,last[maxn],dep[maxn],p[maxn][];

 struct edge{

     int to,pre;

 }e[maxn<<];

 void read(int &k){

     k=; int f=; char c=getchar();

     while (c<''||c>'')c=='-'&&(f=-),c=getchar();

     while (''<=c&&c<='')k=k*+c-'',c=getchar();

     k*=f;

 }

 void add(int x,int y){

     e[++tot].to=y;

     e[tot].pre=last[x];

     last[x]=tot;

 }

 void dfs(int u,int fa){

     dep[u]=dep[fa]+; p[u][]=fa;

     for (int i=;i<=log2(dep[u]);i++) p[u][i]=p[p[u][i-]][i-];

     for (int i=last[u],to=e[i].to;i;i=e[i].pre,to=e[i].to)

     if (to!=fa) dfs(to,u);

 }

 int lca(int x,int y){

     if (dep[x]<dep[y]) swap(x,y);

     if (dep[x]>dep[y])

     for (int i=log2(dep[x]-dep[y]+);i>=,dep[x]!=dep[y];i--)

         if (dep[p[x][i]]>=dep[y]) x=p[x][i];

      if (x==y) return x;

      for (int i=log2(dep[x]);i>=;i--)

      if (p[x][i]!=p[y][i]) x=p[x][i],y=p[y][i];

      return p[x][];

 }

 int main(){

     read(n);

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

         read(x); read(y);

         add(x,y); add(y,x);

     }

     dfs(,);

     read(m); read(x);

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

         read(y);

         ans+=dep[x]+dep[y]-(dep[lca(x,y)]<<);

         x=y;

     }

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

     return ;

 }