%{
    #include <stdio.h>
    extern int yylex(void);
    extern void yyerror(const char*);
%}

%token SEMICOLON TIMES CARPET CLEANED ON DONE DATE INTEGER NONINTEGER
%define parse.error verbose
%start input

%%

input : commands donecommand ;

donecommand : DONE SEMICOLON ;

commands : command commands | %empty ;

command : CARPET INTEGER area SEMICOLON
        | CLEANED CARPET INTEGER ON DATE SEMICOLON
        ;

area : number | number TIMES number ;

number : INTEGER | NONINTEGER;

%%

int main(void) {
    printf("Write a complete input, ending with \"done\", a semicolon and EOF:\n");
    yyparse();
    printf("Ok!\n");
    return 0;
}

void yyerror(const char *s) {
    printf("Incorrect calendar input! Error message: %s\n", s);
}

int yywrap(void) {
    return 1;
}