%{
#include <stdio.h>
%}

%%

"int"      { printf("Keyword: int\n"); }
"float"    { printf("Keyword: float\n"); }
"return"   { printf("Keyword: return\n"); }

[0-9]+     { printf("Number: %s\n", yytext); }
[A-Za-z_][A-Za-z0-9_]* { printf("Identifier: %s\n", yytext); }

.          { /* Ignore other characters */ }

%%

int main() {
    printf("Enter a string: ");
    yylex();
    return 0;
}