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Pascal was designed in 1970 by Niklaus Wirth as a language for teaching structured programming. It dominated CS education in the 80s and 90s. Today Free Pascal (FPC) keeps the dialect alive and is what Judge0 uses.

program Hello;
begin
    WriteLn('Hello, Pascal!');
end.

The shape of every Pascal program:

• program Name; — declares the program (mostly for documentation)
• begin ... end. — the main block. Note the trailing .
• Statements end with ; (separator, not terminator — the last end. doesn't need a ;)
• Strings use single quotes only. Double quotes don't exist.
• Identifiers are case-insensitive: WriteLn = writeln = WRITELN
• Comments: { ... } or (* ... *)

Write and WriteLn

WriteLn prints its arguments and then moves to a new line. Write prints and stays put. Both take a comma-separated list of mixed values:

Write('a');
Write('b');
WriteLn('c');        { one line: abc }
WriteLn('n = ', 42); { n = 42 }

Nearly every exercise here expects one value per line, so WriteLn is the one you want.

The unterminated-string trap

Because a literal is delimited by ' on both ends, forgetting the closing quote does not run off into the next line the way it might elsewhere — FPC stops at the end of the line and reports:

main.pas(3,13) Fatal: String exceeds line

If you see String exceeds line, count the quotes on the line it names.