#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <string.h>
#include <queue>
using namespace std;
const int INF = 999999999;
int n,m,limit,num;
int dis[60][60]; ///记录两点之间的距离
int jw[60];
struct Node{
    int x,y,step,geshu;
}s;
char graph[60][60];
bool vis[60][60];
int dir[][2]={{1,0},{-1,0},{0,1},{0,-1}};
bool check(int x,int y){
    if(x<1||x>n||y<1||y>m||vis[x][y]||graph[x][y]==‘*‘) return false;
    return true;
}
void bfs(Node s,int k){
    queue<Node> q;
    vis[s.x][s.y] = true;
    s.geshu = 1;
    q.push(s);
    while(!q.empty()){
        Node now = q.front();
        q.pop();
        if(now.geshu==num+2) return;
        for(int i=0;i<4;i++){
            Node next;
            next.x = now.x+dir[i][0];
            next.y = now.y+dir[i][1];
            if(!check(next.x,next.y)) continue;
            char c = graph[next.x][next.y];
            next.step = now.step+1;
            next.geshu = now.geshu+1;
            if(c==‘.‘) next.geshu-=1;
            if(c==‘@‘){
                dis[k][0] = next.step;
            }
            else if(c>=‘A‘&&c<=‘J‘) {
                dis[k][c-‘A‘+1] = next.step;
            }else if(c==‘<‘){
                dis[k][num+1] = next.step;
            }
            vis[next.x][next.y] = true;
            q.push(next);
        }
    }
}
bool vis1[60];
int MAX = 0,sum;
void dfs(int u,int step,int ans){
    if(step>limit || MAX == sum) return ; ///必须要加剪枝
    if(u==num+1){
        MAX = max(MAX,ans);
        return;
    }
    for(int i=0;i<=num+1;i++){
        if(!vis1[i]){
            vis1[i] = true;
            dfs(i,step+dis[u][i],ans+jw[i]);
            vis1[i] = false;
        }
    }
}
int main(){
    int tcase;
    scanf("%d",&tcase);
    int  kk = 1;
    while(tcase--){
        for(int i=0;i<30;i++){
            for(int j=0;j<30;j++){
                dis[i][j] = (i==j)?0:INF;
            }
        }
        scanf("%d%d%d%d",&m,&n,&limit,&num);
        sum = 0;
        for(int i=1;i<=num;i++){
            scanf("%d",&jw[i]);
            sum+=jw[i];
        }
        jw[num+1] = jw[0] = 0;
        for(int i=1;i<=n;i++){
            scanf("%s",graph[i]+1);
        }
        for(int i=1;i<=n;i++){
            for(int j=1;j<=m;j++){
                if(graph[i][j]==‘@‘) {
                    memset(vis,false,sizeof(vis));
                    s.x = i,s.y = j,s.step=0;
                    bfs(s,0);
                }
                if(graph[i][j]==‘<‘){
                    memset(vis,false,sizeof(vis));
                    s.x = i,s.y = j,s.step=0;
                    bfs(s,num+1);
                }
                if(graph[i][j]>=‘A‘&&graph[i][j]<=‘J‘){
                    memset(vis,false,sizeof(vis));
                    s.x = i,s.y = j,s.step=0;
                    bfs(s,graph[i][j]-‘A‘+1);
                }
            }
        }
        printf("Case %d:\n",kk++);
        if(dis[0][num+1]>limit){
            printf("Impossible\n");
            if(tcase) printf("\n");
            continue;
        }
        memset(vis1,false,sizeof(vis1));
        MAX = 0;
        vis1[0] = true;
        dfs(0,0,0);
        printf("The best score is %d.\n",MAX);
        if(tcase) printf("\n");
    }
}