class Squares:
    def __init__(self, start, stop):
        self.value = start -1
        self.stop = stop
        self.start =start
        
    def __iter__(self):
        return self
    
    def next(self):
        if self.value ==self.stop:
            self.value= self.start -1
            raise StopIteration
        self.value +=1
        return self.value**2