#include <stdio.h>
#include <math.h>
#include <iostream>
#include <algorithm>
#include <math.h>
#include <stdlib.h>
#include <string.h>
using namespace std;
const int N = 1005;
const int M = N*N;
int n,m;
int a[N][N];
int father[M];
struct Edge{
    int u,v,w;
}edge[2*M];
int _find(int x){
    if(x!=father[x]) father[x] = _find(father[x]);
    return father[x];
}
int cmp(Edge a,Edge b){
    return a.w<b.w;
}
int kruskal(int m){
    sort(edge+1,edge+m,cmp);
    int cost = 0;
    for(int i=1;i<m;i++){
        int x = _find(edge[i].u);
        int y = _find(edge[i].v);
        if(x!=y){
            father[x] = y;
            cost+=edge[i].w;
        }
    }
    return cost;
}
int main()
{
    int tcase;
    scanf("%d",&tcase);
    int t = 1;
    while(tcase--){
        scanf("%d%d",&n,&m);
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                father[i*m+j] = i*m+j;
                scanf("%d",&a[i][j]);
            }
        }
        int id = 1;
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                int u = i*m+j;
                if(i>0){
                    int v = (i-1)*m+j;
                    edge[id].u = u;
                    edge[id].v = v;
                    edge[id++].w = abs(a[i][j]-a[i-1][j]);
                }
                if(j>0){
                    int v = i*m+j-1;
                    edge[id].u = u;
                    edge[id].v = v;
                    edge[id++].w = abs(a[i][j]-a[i][j-1]);
                }
            }
        }
        int cost = kruskal(id);
        printf("Case #%d:\n%d\n",t++,cost);
    }
}