diff --git a/NonLinearSolver/modelReduction/Tree.cpp b/NonLinearSolver/modelReduction/Tree.cpp
index e00abd926827ab13449157c16b9af3d2b7b99711..185581bb43f57cfa230ca5739b0517fd8828f4ca 100644
--- a/NonLinearSolver/modelReduction/Tree.cpp
+++ b/NonLinearSolver/modelReduction/Tree.cpp
@@ -311,7 +311,15 @@ void Tree::createRandomTreeSameDepthForNodes(int nbLeaves, int numChildMax, int
         }
         else
         {
-          outPut.push_back(numChilds+remaining);
+          if (numChilds+remaining < 4)
+          {
+            outPut.push_back(numChilds+remaining);
+          }
+          else
+          {
+            outPut.push_back(2);
+            outPut.push_back(numChilds+remaining-2);
+          }
           iter += numChilds+remaining;
         }
       };
diff --git a/cm3apps/installAPC.txt b/cm3apps/installAPC.txt
new file mode 100644
index 0000000000000000000000000000000000000000..17b7894848f669b08d42056a7be73e79045bf073
--- /dev/null
+++ b/cm3apps/installAPC.txt
@@ -0,0 +1,30 @@
+
+connect acpc with cable AND usb cable to station
+sudo apt-get install apcupsd
+
+possibly change vi /etc/apcupsd/apcupsd.conf
+UPSNAME smartupsC1500
+UPSCABLE usb
+UPSTYPE usb
+DEVICE 
+POLLTIME 60
+
+BATTERYLEVEL 10
+
+MINUTES 10
+
+TIMEOUT 0
+
+sudo vi /etc/default/apcupsd
+ISCONFIGURED=yes
+
+sudo systemctl restart apcupsd
+
+check
+apcaccess status
+
+to test it
+sudo systemctl stop apcupsd
+sudo apctest
+
+