#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<cstdlib>
#include<string>
#include<queue>
#include<vector>
#include<set>
using namespace std;
const int MAX=105;
int grid[MAX][MAX];
bool vis[MAX][MAX];
int d[4][2]={{-1,0},{1,0},{0,1},{0,-1}};
int n,m;
int max(int a,int b)
{
	return a>b?a:b;
}
void dfs(int i,int j,int h)
{
	if(i<1||j<1||i>n||j>m||vis[i][j]||grid[i][j]>h)
		return;
	vis[i][j]=true;
	grid[i][j]=0;
	for(int k=0;k<4;k++)
		dfs(i+d[k][0],j+d[k][1],h);
}
void dfs2(int i,int j)
{
	if(i<1||j<1||i>n||j>m||vis[i][j]||(!grid[i][j]))
		return;
	vis[i][j]=true;
	for(int k=0;k<4;k++)
		dfs2(i+d[k][0],j+d[k][1]);
}
bool check(int h)
{
	int i,j,cnt=0;
	memset(vis,0,sizeof(vis));
	for(i=1;i<=m;i++)
		if(!vis[1][i])
			dfs(1,i,h);
	for(i=1;i<=n;i++)
		if(!vis[i][1])
			dfs(i,1,h);
	for(i=1;i<=m;i++)
		if(!vis[n][i])
			dfs(n,i,h);
	for(i=1;i<=n;i++)
		if(!vis[i][m])
			dfs(i,m,h);
	memset(vis,0,sizeof(vis));
	for(i=1;i<=n;i++)
		for(j=1;j<=m;j++)
			if(!vis[i][j]&&grid[i][j])
			{
				cnt++;
				dfs2(i,j);
			}
	if(cnt<=1)
		return 1;
	else
		return 0;
}
int main()
{
	int ca=0,i,j,maxx=-1,cnt,ans;
	while(scanf("%d%d",&n,&m)!=EOF)
	{
		if(n==0&&m==0)
			break;
		cnt=0;
		ans=-1;
		memset(grid,0,sizeof(grid));
		for(i=1;i<=n;i++)
			for(j=1;j<=m;j++)
			{
				scanf("%d",&grid[i][j]);
				maxx=max(maxx,grid[i][j]);
			}
		for(i=1;i<=maxx;i++)
			if(!check(i))
			{
				ans=i;
				break;
			}
		printf("Case %d: ",++ca);
		if(ans==-1)
			printf("Island never splits.\n");
		else
			printf("Island splits when ocean rises %d feet.\n",ans);
	}
	return 0;
}