11588

#include <iostream>
#include <cstdio>
#include <sstream>
#include <string>
#include <cstring>

using namespace std;
int arr[27];
int main()
{
	int t,ans;
	int kase=1;
	char ch;
	int R,C,M,N;
	cin>>t;

	while(t--)
	{
		cin>>R>>C>>M>>N;
		memset(arr,0,sizeof(arr));
		for(int i=0;i<R*C;i++)
		{
			cin>>ch;
			arr[ch-'A']+=1;
		}
		int mx=-1;
		for(int i=0;i<26;i++)
		{
			if(arr[i]>mx)
			mx=arr[i];
		}
		int cnt=0;
		for(int i=0;i<26;i++)
		{
			if(arr[i]==mx)
			cnt+=1;
		}
		ans=mx*cnt*M+(R*C-mx*cnt)*N;
		cout<<"Case "<<kase++<<": "<<ans<<"\n";
	}
	return 0;
}