ros/ros.h: No such file or directory

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Hello, I'm new to ROS, and I have some trouble with my first file. When I include: #include "ros/ros.h" in VSCode, it says "ros/ros.h: No such file or directoy". I'm using ROS Melodic on Ubuntu 18.04.

Here is my CMakeLists.text:

cmake_minimum_required(VERSION 3.0.2)
project(helloworld)
find_package(catkin REQUIRED COMPONENTS
  roscpp
  rospy
  std_msgs
)
catkin_package()
include_directories(
  ${catkin_INCLUDE_DIRS}
)
add_executable(hello src/helloworld.cpp)
target_link_libraries(hello ${catkin_LIBRARIES})

Package.xml:

<?xml version="1.0"?>
<package format="2">
<name>helloworld</name>
<version>0.0.0</version>
<description>The helloworld package</description>
<maintainer email="dell@todo.todo">dell</maintainer>
<license>TODO</license>

 <buildtool_depend>catkin</buildtool_depend>
 <build_depend>roscpp</build_depend>
 <build_depend>rospy</build_depend>
 <build_depend>std_msgs</build_depend>

 <build_export_depend>roscpp</build_export_depend>
 <build_export_depend>rospy</build_export_depend>
 <build_export_depend>std_msgs</build_export_depend>
 <exec_depend>roscpp</exec_depend>
 <exec_depend>rospy</exec_depend>
 <exec_depend>std_msgs</exec_depend>

 <export>
 <!-- Other tools can request additional information be placed here -->
 </export>
 </package>

C_cpp.properities.json:

  {

"configurations": [
    {
        "browse": {
            "databaseFilename": "",
            "limitSymbolsToIncludedHeaders": true,
            "path": [
             "/opt/ros/melodic/include",
             "/usr/include"
        ]
    },
    "includePath": [
                "/opt/ros/melodic/include/**",
                "/usr/include/**",
                "/opt/ros/melodic/include"
            ],
            "name": "ROS",
            "cppStandard": "c++17",
            "intelliSenseMode": "gcc-x64",
            "compilerPath": "/usr/bin/gcc"
        }
    ],
    "version": 4
}

tasks.json:

{
    "version": "2.0.0",
    "tasks": [
        {
            "label": "catkin_make:debug",
            "type":"shell",
            "command":"catkin_make",
            "args": [
                "-I", "/opt/ros/melodic/include",
                "-I", "${workspaceFolder}"
             ],
            "group": {
            "kind": "build",
            "isDefault": true
             },
    "presentation": {
        "echo": true,
        "reveal": "always",
        "focus": false,
        "panel": "shared",
        "showReuseMessage": true,
        "clear": false
    },
    "problemMatcher":"$msCompile"
        }
    ]
}

And I have found "ros" directory using cd /opt/ros/melodic/include and ls. I'm quite confused now. Thanks for your help.