%{
#include <stdio.h>
a = 10 + 20;
%}

%%

[0-9]+            { printf("NUMBER: %s\n", yytext); }
[a-zA-Z_][a-zA-Z0-9_]*   { printf("IDENTIFIER: %s\n", yytext); }
[+\-*/]           { printf("OPERATOR: %s\n", yytext); }
[\t\n\r ]+        { /* Ignore whitespace */ }
.                 { printf("UNKNOWN CHARACTER: %s\n", yytext); }

%%

int main() {
    yylex();  // Calls the lexical analyzer
    return 0;
}

int yywrap() {
    return 1;  // Indicates end of input
}