class Tank(object):
    
    def __init__(self, name):
        
        self.name = name
        self.alive = True
        self.ammo = 5
        self.armor = 60
        
    def __str__(self):
        
        if self.alive:
            return "%s (%i armor, %i shells)"%(self.name, self.armor, self.ammo)
            #return self.name+"  ("+str(self.armor)+" armor, "+str(self.ammo)+" shells)"
        else:
            return "%s (DEAD)"%self.name
        
    def fire_at(self, enemy):
        
        if self.ammo >= 1:
            self.ammo-= 1
            print self.name, "fires on", enemy.name
            enemy.hit()            
        else:
            print self.name, "has no shells!"
            
    def hit(self):
        
        self.armor-= 20
        print self.name, "is hit!"
        if self.armor <= 0:
            self.explode()
            
    def explode(self):
        
        self.alive = False
        print self.name, "explodes!"