Merge branch 'double'

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

main.cpp

@@ -5,7 +5,7 @@ using namespace std;
 int main()
 {
     cout << "Enter A and B: ";
-           int a, b;
+           double a, b;
            cin >> a >> b;
            cout << "A + B = " << a + b << '\n'
                 << "A - B = " << a - b << '\n'