// Tflood.cc
// ecna2009
// problem E - The Flood

#include <iostream>
using namespace std;

const int MAX = 200;
const int BIG = 1000001;
int m, n, Alt[MAX+1][MAX+1], Water[MAX+1][MAX+1], Mark[MAX+1][MAX+1];
int Min;

void GetGrid(int m, int n){
  for(int i=1;i<=m;i++)
    for(int j=1;j<=n;j++)
      cin>>Alt[i][j];
  for(int j=0;j<=n+1;j++)
    Alt[0][j]=Water[0][j]=Alt[m+1][j]=Water[m+1][j]=0;
  for(int i=1; i<=m;i++)
    Alt[i][0]=Water[i][0]=Alt[i][n+1]=Water[i][n+1]=0;   

  //init Water[][] - not ocean as far as we know
  for(int i=1;i<=m;i++)
    for(int  j=1;j<=n+1; j++)
      Water[i][j]=1;
}

void ZeroOutMark(int m,int n){
  for(int i=0; i<=m+1; i++)
    for(int j=0; j<=n+1; j++)
      Mark[i][j]=0;            // mark as "not yet visited"
}

void Flood(int i, int j){
  if(Mark[i][j]==0){
    Mark[i][j]=1;
    if(Alt[i][j]<=0){    //flood this spot
     Water[i][j]=Alt[i][j]=0;
     if(i>0) Flood(i-1,j);
     if(i<=m) Flood(i+1,j);
     if(j>0) Flood(i,j-1);
     if(j<=n) Flood(i,j+1);
    }
  }
}

// for debugging
void PrintGrids(int  m, int n){
  cout<<"Alt[][]     Water[][]     Mark[][]"<<endl;
  for(int i=0;i<=m+1;i++){
    for(int j=0;j<=n+1;j++)
     cout<<Alt[i][j]<<' ';
    cout<<"   ";
    for(int j=0;j<=n+1;j++)
     cout<<Water[i][j]<<' ';
    cout<<"   ";
    for(int j=0;j<=n+1;j++)
     cout<<Mark[i][j]<<' ';
    cout<<endl;
  }
}

int FindMin(int i, int j){
  if(Mark[i][j]==0){
    Mark[i][j]=1;
    if(Water[i][j] && Alt[i][j]<Min)  
       Min = Alt[i][j];
    if(Water[i][j]) return Min;
    // know Water[i][j] == 0
    if(i>0) Min = FindMin(i-1,j);
    if(i<=m) Min = FindMin(i+1,j);
    if(j>0) Min = FindMin(i,j-1);
    if(j<=n) Min = FindMin(i,j+1);
  }
  return Min;
}

void Decrement(int Min, int  m, int  n){
  for(int i=1;i<=m;i++)
    for(int j=1;j<=n;j++)
      if(Water[i][j]>0) Alt[i][j] -= Min;
}

void FillLand(int i, int  j){
// know Water[i][j]==1 (is land)
Mark[i][j]=1;
if (Water[i-1][j] && Mark[i-1][j]==0) FillLand(i-1,j);
if (Water[i+1][j] && Mark[i+1][j]==0) FillLand(i+1,j);
if (Water[i][j-1] && Mark[i][j-1]==0) FillLand(i,j-1);
if (Water[i][j+1] && Mark[i][j+1]==0) FillLand(i,j+1);
}

// check if disconnected
bool TwoPieces(int m, int n){
  //find some land (we  know there's some)
  int  i=1,  j=1;
  while(Water[i][j]==0){
    j++;
    if(j>n) { i++; j=1;}
  }
  //[i][j] is land
  FillLand(i,j);
  for(int i=1;i<=m;i++)
    for(int j=1;j<=n;j++)
      if(Mark[i][j]==0 && Water[i][j]) return true;
  return false;
}

int main(){
  int CaseNo=1, height;
  bool Done;

  cin>>m>>n;
  while(m>0){
    Done = false;
    GetGrid(m,n);
    ZeroOutMark(m,n);
    Flood(0,0);

    height = 0;
    while (!Done){
      Min = BIG;
      ZeroOutMark(m,n);
      Min = FindMin(0,0);

      if(Min==BIG){  // all underwater
        cout<<"Case "<<CaseNo++<<": Island never splits."<<endl;
        Done = true;
      } else {
        //check if split
        ZeroOutMark(m,n);
        if(TwoPieces(m,n)){
          cout<<"Case "<<CaseNo++<<": Island splits when ocean rises "<<height<<" feet."<<endl;
          Done = true;
        } else {
          Decrement(Min,m,n);
          height += Min;
          ZeroOutMark(m,n);
          Flood(0,0);
        }
      }
    }
    cin>>m>>n;
  }

return 0;
}