#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<string>
#include<algorithm>
#define maxn 30+5
using namespace std;
int main(){
int m,n,total,sum,t,flag,num=0;
int a[maxn][maxn],ss[maxn*maxn];
double k,x,z;
while(scanf("%d%d",&m,&n)==2){
if(m==0&&n==0) break;
num++;
sum=0,t=0,flag=1;
memset(a,0,sizeof(a));
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
scanf("%d",&a[i][j]);
sum+=a[i][j];
ss[t++]=a[i][j];
}
}
sort(ss,ss+t);
scanf("%d",&total);
z=n*m; //z代表方格数
k=total/100.00;
while(flag==1){
x=(k+sum)/z;
if(x<ss[t-1]){
sum-=ss[t-1];
t--;
z--;
}else{
flag=0;
printf("Region %d
",num);
printf("Water level is %.2lf meters.
",x);
k=z/(n*m)*100;
printf("%.2lf percent of the region is under water.
",k);
printf("
");
}
}
}
return 0;
}