#include <windows.h>
#include <math.h>
#include <stdlib.h>

HWND hedit, hedit2;
int vl, vl2;

LONG WINAPI WndProc(HWND, UINT, WPARAM, LPARAM);


int WINAPI WinMain(HINSTANCE hInstance,
        HINSTANCE hPrevInstance,
        LPSTR lpCmdLine,
        int nCmdShow)
{
    HWND hwnd;
    MSG msg;
    WNDCLASS w;
        memset(&w, 0, sizeof (WNDCLASS));
        w.style = CS_HREDRAW | CS_VREDRAW;
        w.lpfnWndProc = WndProc;
        w.hInstance = hInstance;
        w.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
        w.lpszClassName = "My Class";
    RegisterClass(&w);
    hwnd = CreateWindow("My Class", "primer",
            WS_OVERLAPPEDWINDOW,
            500, 300, 500, 380, NULL, NULL, hInstance, NULL);

    hedit = CreateWindow("edit", "0", WS_CHILD | WS_VISIBLE | ES_LEFT,
            10, 10, 80, 30, hwnd, (HMENU) 10000, hInstance, NULL);

    hedit2 = CreateWindow("edit", "0", WS_CHILD | WS_VISIBLE | ES_LEFT,
            150, 10, 80, 30, hwnd, (HMENU) 10001, hInstance, NULL);

    CreateWindow("button", "+", WS_CHILD | WS_VISIBLE | BS_DEFPUSHBUTTON,
                  10, 100, 40, 20, hwnd, (HMENU) 1000, hInstance, NULL);

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

LONG WINAPI WndProc(HWND hwnd, UINT Message, WPARAM wparam, LPARAM lparam) {
    TCHAR val[33] = {0};
    switch (Message)
    {
            case WM_DESTROY: PostQuitMessage(0);
            break;
        case WM_COMMAND:
        {
            switch (LOWORD(wparam))
            {
                    case 1000:
                {
                    GetWindowText(hedit, val, 33);
                    vl = atoi(val);
                    GetWindowText(hedit2, val, 33);
                    vl2 = atoi(val);
                    int res = vl + vl2;
                    itoa(res, val, 10);
                    MessageBox(hwnd, LPSTR(resCHR), "Результат", MB_OK);
                }
            }
        };
        default: return DefWindowProc(hwnd, Message, wparam, lparam);
    }
    return 0;
}