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/install.txt b/cm3apps/install.txt
index 48b68a813b0916d3f5b21751af6fe4c62ed5b6af..41516f33d0fc6454793e020cf973c65b8bb0cf41 100644
--- a/cm3apps/install.txt
+++ b/cm3apps/install.txt
@@ -492,8 +492,8 @@ C) Install Open Cascade (optional)
 D) Install Torch
         cd local
        // no gpu
-        wget https://download.pytorch.org/libtorch/cpu/libtorch-shared-with-deps-1.4.0%2Bcpu.zip
-        unzip libtorch-shared-with-deps-1.4.0+cpu.zip 
+          wget https://download.pytorch.org/libtorch/cpu/libtorch-shared-with-deps-1.4.0%2Bcpu.zip
+          unzip libtorch-shared-with-deps-1.4.0+cpu.zip 
        // gpu
            1) clean up
            sudo rm /etc/apt/sources.list.d/cuda*
@@ -519,16 +519,14 @@ D) Install Torch
            4) install cudnn 
            download cudnn from nvidia (you need to register and downloadmanualy
            https://developer.nvidia.com/compute/machine-learning/cudnn/secure/8.0.4/11.0_20200923/cudnn-11.0-linux-x64-v8.0.4.30.tgz
-
-
-
-
-A
-A
-
-        sudo apt-get install nvidia-cuda-toolkit
-        //check version nvcc --version
-        wget https://download.pytorch.org/libtorch/cu110/libtorch-shared-with-deps-1.7.0%2Bcu110.zip
+           copy in your local directory
+           tar xvf cudnn-11.0-linux-x64-v8.0.4.30.tgz
+           sudo cp cuda/include/cudnn*.h /usr/local/cuda/include
+           sudo cp cuda/lib64/libcudnn* /usr/local/cuda/lib64
+           sudo chmod a+r /usr/local/cuda/include/cudnn*.h /usr/local/cuda/lib64/libcudnn*
+           5) download torch with gpu
+           wget https://download.pytorch.org/libtorch/cu110/libtorch-shared-with-deps-1.7.0%2Bcu110.zip
+           unzip libtorch-shared-with-deps-1.7.0%2Bcu110.zip
 
 
         add export TORCHDIR=$HOME/local/libtorch in your .bashrc