diff --git a/cave.cpp b/cave.cpp
index 0c44d3e..15ae3b0 100644
--- a/cave.cpp
+++ b/cave.cpp
@@ -3,15 +3,21 @@
 #include <iostream>
 using namespace std;
 static int SEED = 65536; //test seed
+void air(x,y,z) {
+    //TODO
+}
 int sphere(x,y,z,r) {
     int xx = 0, yy = 0, zz = 0;
-    int pos[3] = [x,y,z]
+    int pos[3] = [x,y,z];
+    int length
     for (xx = 0 - r; xx < r + 1; xx++) {
         for (yy = 0 - r; yy < r + 1; yy++) {
             for (zz = 0 - r; zz < r + 1; zz++) {
-                pos[0] = x + xx;
-                pos[1] = y + yy;
-                pos[2] = z + zz;
+                pos[0] = x + xx; pos[1] = y + yy; pos[2] = z + zz;
+                length = sqrt(pow(pos[0],2) + pow(pos[1],2) + pow(pos[2],2));
+                if (length < r) {
+                    air(x,z,y);
+                }
             }
         }
     }