#include <iostream>
using namespace std;

int main()
{
    int R1, R2;
    float Rpar;
    cout << "Enter the value for R1: " ;
    cin >> R1;
    cout << "Enter the value for R2: ";
    cin >> R2;
    Rpar = (R1 * R2) / (R1 + R2);
    cout <<"The value of parallel resistance is: " << Rpar << "\n";
    system ("pause");
    return 0;
    
   }

#include <windows.h> /* Windows header */

LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
char szClassName[ ] = "WindowsApp";   /* Class ID */

int WINAPI
WinMain (HINSTANCE hThisInstance,
HINSTANCE hPrevInstance,
LPSTR lpszArgument,
int nFunsterStil)

{
        HWND hwnd;
        MSG messages;
        WNDCLASSEX wincl;

        wincl.hInstance = hThisInstance;
        wincl.lpszClassName = szClassName;
        wincl.lpfnWndProc = WindowProcedure; /* See end of code */
        wincl.style = CS_DBLCLKS;
        wincl.cbSize = sizeof (WNDCLASSEX);
        wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
        wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
        wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
        wincl.lpszMenuName = NULL;
        wincl.cbClsExtra = 0;
        wincl.cbWndExtra = 0;
        wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND; /* Default windows background colour */

        if (!RegisterClassEx (&wincl))
        return 0;

        hwnd = CreateWindowEx (
        0,
        szClassName,         /* Classname */
        "Windows App",       /* Title Text */
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,       /* Default x... */
        CW_USEDEFAULT,       /* ...and default y position of window */
        640,                 /* The programs width... */
        480,                 /* ...and height in pixels */
        HWND_DESKTOP,
        NULL,
        hThisInstance,
        NULL
        );

        /* Make the window visible on the screen */
        ShowWindow (hwnd, nFunsterStil);
        while (GetMessage (&messages, NULL, 0, 0))
        {
                TranslateMessage(&messages);
                DispatchMessage(&messages);
        }

        /* Return: wParam from a quit message usually = 0 */
        return messages.wParam;
}

LRESULT CALLBACK
WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{ /* Called when window processes a message */
        switch (message)
        {
                case WM_DESTROY: /* Destoy message: called if you press the "x" in the top right corner */
                PostQuitMessage (0); /* Send a message to quit */
                break;
                default:
                return DefWindowProc (hwnd, message, wParam, lParam);
        }
        return 0;
}