#include <regex.h>
#include <stdio.h>
 
int checkregex(char *in){
  regex_t regex;
  char *expression="^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$";
  int reti;
  char msgbuf[100];
 
  /* Compile regular expression */
  reti = regcomp(&regex, expression, REG_EXTENDED);
  if (reti) {
    fprintf(stderr, "Could not compile regex\n");
    return -1;
  }
 
  /* Execute regular expression */
  reti = regexec(&regex, in , 0, NULL, 0);
  if (!reti) {
    printf("Match\n");
    return 1;
  }
  else if (reti == REG_NOMATCH) {
    printf("No match\n");
    return 0;
  }
  else {
    regerror(reti, &regex, msgbuf, sizeof(msgbuf));
    fprintf(stderr, "Regex match failed: %s\n", msgbuf);
    exit(1);
  }
  return 0;
}
 
int main(void) { 
    int x = checkregex("XII");
	printf("%d\n", x);
	return 0;
}

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