%{
#include <stdio.h>
#include <stdlib.h>
%}
 
%%
[0-9]+      { printf("NUMBER: %s\n", yytext); }
[ \t\n]     ;  /* Skip whitespace */
"+"         { printf("ADD\n"); return '+'; }
"-"         { printf("SUBTRACT\n"); return '-'; }
"*"         { printf("MULTIPLY\n"); return '*'; }
"/"         { printf("DIVIDE\n"); return '/'; }
.           { printf("Invalid character: %s\n", yytext); return 0; }
%%
 
int main() {
    printf("Enter expression (e.g., 2+3, 10*5, etc.):\n");
    int token;
    while((token = yylex()) != 0) {
        // Loop until there are no more tokens
    }
    return 0;
}
 

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