How to pass correct input in OOPS codekata?

Sample Input : a = 3 b = 4 c = 5

i need to pass only number(3,4,5) without a=,b=,c= ..

how to do it?

class Triangle:
    def __init__(self,a,b,c):
        self.a=a
        self.b=b
        self.c=c
    def perimeter(self):
        output = self.a + self.b + self.c
        return 'Perimeter is = {}'.format(output)
    def area(self):
        s = (self.a+self.b+self.c)/2
        output = s*(s-self.a)*(s-self.b)*(s-self.c)
        return  'Area is = {}'.format(output**0.5)
    
triangle =Triangle(int(input()),int(input()),int(input()))
triangle.area()
triangle.perimeter()