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

%token SPECIES DECLARATIONS DONE NAME OBSERVATION OBSERVATIONS NUMBER
%define parse.error verbose
%start input

%%

input : manydeclarations DECLARATIONS DONE manyobservations OBSERVATIONS DONE { printf("Done!\n"); }
      ;

manydeclarations : onedeclaration manydeclarations
                 | %empty
                 ;

onedeclaration : SPECIES NAME
               ;

manyobservations : oneobservation manyobservations
                 | %empty
                 ;

oneobservation : OBSERVATION NAME NUMBER
               ;

%%

int main() {
    printf("Enter a complete animal input. End with the keyword \"done\" and EOF.\n");
    yyparse();
    printf("Ok!\n");
    return 0;
}

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

int yywrap(void) {
    return 1;
}