#include "stdio.h"

 #include "stdlib.h"

 #include "string.h"

 #define FIN freopen("input.txt","r",stdin)

 #define FOUT freopen("output.txt","w",stdout)

 int main()

 {

     //FIN;

     //FOUT;

     int m, n;

     int data[],kase=;

     double level, percentage, high = ,sum;

     while (scanf("%d%d",&m,&n)==&&n!=&&m!=)

     {

         kase++;

         for (int i = ; i < m*n; i++)

         {

             scanf("%d", &data[i]);

         }

         high = ;

         scanf("%lf", &sum);

         sum /= ;//正方形为10*10，化简一下sum

         //排序

         for (int i = ; i < m*n; i++)

         {

             for (int j = i + ; j < m*n; j++)

             {

                 if (data[i] > data[j])

                 {

                     int ex = data[i];

                     data[i] = data[j];

                     data[j] = ex;

                 }

             }

         }

         //data[m*n] = 100000;//最大的边界

         //输出

         /*printf("排序后:\n");

         for (int i = 0; i < m*n; i++)

         {

             printf("%-4d", data[i]);

             if ((i + 1) % m == 0)

                 printf("\n");

         }*/

         for (int i = ; i < n*m; i++)

         {

             if (sum != - && i == m*n - )//找到最后一个说明淹没了

             {

                 high += (sum*1.0) / (i + );

                 high += data[];

                 int cntDown = (i + );

                 percentage = (cntDown*1.0) / (m*n) * ;

                 sum = -;

                 break;

             }

             if ((data[i + ] - data[i])*(i+)< sum)//小就继续往上面走

             {

                 sum -= (data[i + ] - data[i])*(i+);

                 high += data[i+]-data[i];

             }

             else

             {

                 high += (sum*1.0) / (i+);

                 high += data[];

                 int cntDown =(i+);

                 percentage = (cntDown*1.0) / (m*n)*;

                 sum = -;

                 break;

             }

         }

         printf("Region %d\n", kase);

         printf("Water level is %.2f meters.\n",high);

         printf("%.2f percent of the region is under water.\n\n",percentage);

     }

     return ;

 }