The annual snake festival is upon us and all the snakes of the kingdom have gathered to participate in the parade. The chef was tasked with reporting on the parade, so he decided to watch all the snakes first. When he sees the snake first, it will be his head, so he marks the "H". Snakes are long, and when they see the snake finally scurry away, they mark its tail with a "T". In the interim, when the snake is moving around it, or in the time between one snake and the next snake, it marks a '.'. Since the snakes come in a procession and one by one, a valid message would be something like "..H..T...HTH....T.", or "...", or "HT", while "T ...H..H.T", "H..T..H", "H..H..T..T" would be invalid messages (see explanation below). Formally, a snake is represented by an 'H' followed by some (possibly null) '.' and then 'T'. A valid message is one that begins with the (probably zero-length) string '.' and then some (possibly zero) snakes, with some '.'s in between, and finally some (possibly zero) '.'s. The chef was devouring the festival food and was very sleepy. So his message may be invalid. You have to help him find out if his message is valid or not.

A bandit armed with a revolver approached a quaker as he strolled down a rural road. A robbery was in progress, and he said, "Your money or your life!" My buddy answered, "I can't give you my money because then I'd be helping you do evil, but exchange is legal, so here, take my pocketbook in return for your gun." The robber accepted the purse, but the Quaker put the pistol to his head and said, "Now friend, give me back my pocketbook or the weapon may go off fire," as recounted by the thief.

A quaker was walking down a country road when he was suddenly confronted by a robber brandishing a pistol. The robber exclaimed, "Your money or your life!" My friend replied, "I cannot deliver my money because I should be aiding thee in evildoing, but exchange is lawful, and I will give thee my purse for the pistol." The thief consented to accept the purse, then the quaker pointed the gun to the robber's head and said, "Now buddy, give me back my pocketbook or the weapon may go off fire," according to the robber.

A pistol-wielding robber approached a Quaker on a rural road. "Your money or your life!" shouted the thief. "Exchange is allowed, and I will offer thee my purse for the weapon," my buddy said. The thief accepted the handbag, then the quaker held the pistol to his head and said, "Now friend, give me back my pocketbook or the weapon may go off fire," according to the robber.