class polinom:
    #инициализация
    def __init__(self,*args):
        self.v = list(args)
    #сумма
    def __add__(self, other):
        if len(self.v) <= len(other.v):
            s = other
            for i in range(len(self.v)):
                s.v[i]+=self.v[i]
        else:
            s = self
            for i in range(len(other.v)):
                s.v[i]+=other.v[i]
        return s
    def __iadd__(self, other):
        for i in range(min(len(self.v), len(other.v))):
            self.v[i]+=other.v[i]
        if len(other.v) > len(self.v):
            for i in range(len(self.v), len(other.v)):
                self.v.append(-other.v[i])
        return self
    #разность
    def __sub__(self, other):
        s = self
        for i in range(min(len(self.v), len(other.v))):
            s.v[i]-=other.v[i]
        if len(other.v) > len(self.v):
            for i in range(len(self.v), len(other.v)):
                s.v.append(-other.v[i])
        return s
    def __isub__(self, other):
        for i in range(min(len(self.v), len(other.v))):
            self.v[i]-=other.v[i]
        if len(other.v) > len(self.v):
            for i in range(len(self.v), len(other.v)):
                self.v.append(-other.v[i])
        return self
    #строчное представление
    def __str__(self):
        k = 0
        s = ''
        for elem in self.v:
            s += ('+' * (elem >= 0) + str(elem) + 'x^' + str(k)) * (elem !=0)
            k += 1
        if s[0] == '+':
            return s[1:]
        else:
            return s
    #значение полинома от x
    def Xv(self, x):
        s = 0
        k = 0
        for elem in self.v:
            s+=(elem * x**k)
            k+=1
        return s
n = polinom(-1,-2,-3,-4)
n += polinom(1,2,3,4,5)
print((n), n.Xv(1))