C/C++の宿題やらせてください。おながいします

#include <stdio.h>
char *me;
static void die(char *msg){fprintf(stderr, "%s: %s", me, msg); exit(1);}
int main(int argc, char **argv)
{
  char c;
  char s[BUFSIZ];
  int y,m,d;
  me = argv[0];
  if (fgets(s, BUFSIZ, stdin) == NULL) die("couldn't read input\n");
  if (sscanf(s, "%c%d/%d/%d",&c,&y,&m,&d) != 4) die("invalid format\n");
  switch(c) {
    case 'H': y += 1988; break;
    case 'S': y += 1925; break;
    case 'T': y += 1911; break;
    case 'M': y += 1867; break;
    default: die("unknown first letter\n");
  }
  printf("%d年%02d月%02d日\n", y,m,d);
  return 0;
}