Invoking "make" failed

edit

I'm using Ubuntu 12.04 & ROS Hydro. While going through this tutorial here i encountered the following error upon typing:

catkin_make

asaad@VAIO:~/catkin_ws$ catkin_make
Base path: /home/asaad/catkin_ws
Source space: /home/asaad/catkin_ws/src
Build space: /home/asaad/catkin_ws/build
Devel space: /home/asaad/catkin_ws/devel
Install space: /home/asaad/catkin_ws/install
####
#### Running command: "make cmake_check_build_system" in "/home/asaad/catkin_ws/build"
####
####
#### Running command: "make -j4 -l4" in "/home/asaad/catkin_ws/build"
####
[  0%] [  8%] Built target std_msgs_generate_messages_py
[ 16%] [ 16%] Built target std_msgs_generate_messages_cpp
Building CXX object begginer_tutorials/CMakeFiles/add_two_ints_server.dir/src/add_two_ints_server.cpp.o
Building CXX object begginer_tutorials/CMakeFiles/add_two_ints_client.dir/src/add_two_ints_client.cpp.o
[ 16%] Built target std_msgs_generate_messages_lisp
[ 25%] Built target listener
[ 33%] Built target talker
[ 50%] Built target begginer_tutorials_generate_messages_cpp
[ 83%] Built target begginer_tutorials_generate_messages_py
[100%] Built target begginer_tutorials_generate_messages_lisp
[100%] Built target begginer_tutorials_generate_messages
/home/asaad/catkin_ws/src/begginer_tutorials/src/add_two_ints_server.cpp:2:43: fatal error: beginner_tutorials/AddTwoInts.h: No such file or directory
compilation terminated.
/home/asaad/catkin_ws/src/begginer_tutorials/src/add_two_ints_client.cpp:2:43: fatal error: beginner_tutorials/AddTwoInts.h: No such file or directory
compilation terminated.
make[2]: *** [begginer_tutorials/CMakeFiles/add_two_ints_server.dir/src/add_two_ints_server.cpp.o] Error 1
make[1]: *** [begginer_tutorials/CMakeFiles/add_two_ints_server.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
make[2]: *** [begginer_tutorials/CMakeFiles/add_two_ints_client.dir/src/add_two_ints_client.cpp.o] Error 1
make[1]: *** [begginer_tutorials/CMakeFiles/add_two_ints_client.dir/all] Error 2
make: *** [all] Error 2
Invoking "make" failed

I saw the other answers related to this but couldn't find the error myself. EDITED:

The CMakeLists.txt file contains the following data:

cmake_minimum_required(VERSION 2.8.3)
project(begginer_tutorials)

## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
  roscpp
  rospy
  std_msgs
  message_generation
)

## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)


## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()

################################################
## Declare ROS messages, services and actions ##
################################################

## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
##   * add a build_depend and a run_depend tag for each package in MSG_DEP_SET
##   * If MSG_DEP_SET isn't empty the following dependencies might have been
##     pulled in transitively but can be declared for certainty nonetheless:
##     * add a build_depend tag for "message_generation"
##     * add a run_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
##   * add "message_generation" and every package in MSG_DEP_SET to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * add "message_runtime" and every package in MSG_DEP_SET to
##     catkin_package(CATKIN_DEPENDS ...)
##   * uncomment the add_*_files sections below as needed
##     and list every .msg/.srv/.action file to be processed
##   * uncomment the generate_messages entry below
##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)

## Generate messages in the 'msg' folder
 add_message_files(
   FILES
   Num.msg

 )

## Generate services ...