#include <stdio.h>#include <iostream>#include <string.h>using namespace std;const int N=800;const int MAXE=200000;const int inf=1<<30;int head[N],s,t,cnt,ans,ss,tt;int d[N],pre[N];bool vis[N];int q[MAXE];struct Edge{    int u,v,c,w,next;}edge[MAXE];void addedge(int u,int v,int w,int c){    edge[cnt].u=u;    edge[cnt].v=v;    edge[cnt].w=w;    edge[cnt].c=c;    edge[cnt].next=head[u];    head[u]=cnt++;    edge[cnt].v=u;    edge[cnt].u=v;    edge[cnt].w=-w;    edge[cnt].c=0;    edge[cnt].next=head[v];    head[v]=cnt++;}int SPFA(){    int l,r;    memset(pre,-1,sizeof(pre));    memset(vis,0,sizeof(vis));    for(int i=0;i<=t;i++) d[i]=inf;    d[s]=0;    l=0;r=0;    q[r++]=s;    vis[s]=1;    while(l<r)    {        int u=q[l++];        vis[u]=0;        for(int j=head[u];j!=-1;j=edge[j].next)        {            int v=edge[j].v;            if(edge[j].c>0&&d[u]+edge[j].w<d[v])            {                d[v]=d[u]+edge[j].w;                pre[v]=j;                if(!vis[v])                {                    vis[v]=1;                    q[r++]=v;                }            }        }    }    if(d[t]==inf)        return 0;    return 1;}int MCMF(){    int flow=0;    while(SPFA())    {        int u=t;        int mini=inf;        while(u!=s)        {            if(edge[pre[u]].c<mini)                mini=edge[pre[u]].c;                u=edge[pre[u]].u;        }        flow+=mini;        u=t;        ans+=d[t]*mini;        while(u!=s)        {            edge[pre[u]].c-=mini;            edge[pre[u]^1].c+=mini;            u=edge[pre[u]].u;        }    }    return flow;}int main(){    int cas,n,m,k;    scanf("%d",&cas);    int val[20][20],id[20][20];    int now=0;    char str[20];    while(cas--)    {        now++;        int i,j,l;        scanf("%d%d%d",&n,&m,&k);        for(i=1;i<=n;i++)        {            scanf("%s",str+1);            for(j=1;j<=m;j++)                val[i][j]=str[j]-‘0‘;        }        s=0;ss=m*n*2+1;        t=m*n*2+4;tt=m*n*2+3;        for(i=0;i<=t;i++) head[i]=-1;        cnt=0;        for(i=1;i<=n;i++)            for(j=1;j<=m;j++)                id[i][j]=++cnt;        cnt=0;        addedge(tt,ss,0,inf);        addedge(ss,ss+1,0,k);        for(i=1;i<=n;i++)            for(j=1;j<=m;j++)            {                addedge(s,id[i][j],0,1);                addedge(id[i][j]+m*n,t,0,1);                addedge(id[i][j],tt,0,1);                addedge(ss+1,id[i][j]+m*n,0,1);                for(l=j+1;l<=m;l++)                {                    if(val[i][j]==val[i][l]) addedge(id[i][j],id[i][l]+m*n,l-j-1-val[i][j],1);                    else addedge(id[i][j],id[i][l]+m*n,l-j-1,1);                }                for(l=i+1;l<=n;l++)                {                    if(val[l][j]==val[i][j]) addedge(id[i][j],id[l][j]+m*n,l-i-1-val[i][j],1);                    else addedge(id[i][j],id[l][j]+m*n,l-i-1,1);                }            }            ans=0;            int flow=MCMF();            if(flow==m*n) printf("Case %d : %d\n",now,-ans);            else printf("Case %d : -1\n",now);    }    return 0;}