Merge branch 'double'

double # Please enter a commit message to explain why this merge is necessary,

main.cpp

@@ -3,7 +3,7 @@
 int main()
 {
 	std::cout << "Enter A and B:";
-	int a, b;
+	double a, b;
 	std::cin >> a >> b;
 	std::cout << "A + B = " << a + b << '\n'
 		<< "A - B = " << a - b << '\n'