def add_large(a, b, a1, b1): a = list(map(int, a)) a1 = list(map(int, a1)) b = list(map(int, b)) b1 = list(map(int, b1)) max_ab = max(len(a), len(b)) max_ab1 = max(len(a1), len(b1)) a1 = a1[::-1] b1 = b1[::-1] a.extend([0]*(max_ab - len(a))) b.extend([...