include

int main() { std::cout << "Hello World!"; return 0; }

Explanation:

1. The line "#include " is a preprocessor directive that tells the compiler to include the iostream library. This library provides input and output functionality.

2. The line "int main()" is the starting point of the program. It declares the main function, which is where program execution begins.

3. The opening curly brace "{" indicates the start of the main function.

4. The line "std::cout << "Hello World!";" is a statement that prints the text "Hello World!" to the console. "std::cout" is a stream object that represents the standard output (console), and the "<<" operator is used to output the text.

5. The closing semicolon ";" terminates the statement.

6. The line "return 0;" is used to exit the main function and return the value 0 to the operating system. This value typically indicates that the program executed successfully.

7. The closing curly brace "}" marks the end of the main function.

Note: C++ is a case-sensitive language, so make sure to use the correct capitalization for the keywords and library names.