rot13(s)={
  s=Vecsmall(s);
  for(i=1,#s,
    if(s[i]>109&s[i]<123,s[i]-=13,if(s[i]<110&s[i]>96,s[i]+=13,if(s[i]>77&s[i]<91,s[i]-=13,if(s[i]<78&s[i]>64,s[i]+=13))))
  );
  Strchr(s)
};