class Vector:
    def _init_(self,d):
        if(isinstace(d,int)== true):
          self.coords =[0]*d
        else:
            self.coords=d
    def __len__(self):
        return len(self.coords)
    def __getitem__(self, j):
        return self.coords[j]
    def __setitem__(self, j, val):
        self.coords[j]=val
    def __add__(self, other):
        if (len(self) !=len(other)):
            raise ValueError("dimension must agree")
        result = vector(len(self))
        for j in range(len(self)):
            result[j]=self[j]+other[j]
        return result
    def __eq__(self, other):
        return self.coords == other.coords
    def __ne__(self, other):
        return not (self==other)
    def __str__(self):
        return '<'+str(self.coords)[1:-1]+'>'
    def __repr__(self):
        return str(self)
    def __sub__(self, other):
        if (len(self) !=len(other)):
            raise ValueError("dimension must agree")
        result = Vector(len(self))
        for j in range(len(self)):
            result[j]=self[j]-other[j]
        return result
    def __neg__(self):
        x=Vector(len(self))
        for i in range(len(self)):
            x[i]=self[1]*n
        return x
    def __mul__(self, n):
        x=Vector(len(self))
        if(isinstance(n,int)== true):
            for i in range(len(self)):
                x[i]=self[i]
            return sum(x)
    def __rmul__(self, n):
        x=Vector(len(self))
        for i in range(len(self)):
            x[i]=n*self[i]
        return x

v1= Vector(5)
v1[1]=10
v1[-1]=10
print(v1)
v2= Vector([2,4,6,8,10])
print(v2)
u1=-v1+v2
print(u1)
u2 = -v2
print(u2)
u3=3*v2
print(u3)
u4=v2*3
print(u4)
u5=v1*v2
print(u5)