C / C++ / MFC

IMB_MYAPP ACCELERATORS
BEGIN
    "0",            IDM_MY_ACTION,      VIRTKEY, CONTROL, NOINVERT
END

void maximunSegment(vector<int> &V, int &start, int &end){
	int i = 0, j = 0, r = 0, aux = 0;
	start = 0; end = 0;

	while(i < V.size()){
		j = i;
		while(j < V.size() - 1){
			aux += V[j];
			if(aux >= r){
				r = aux;
				start = i + 1; end = j + 1;
			}
			++j;
		}
		aux = 0;
		++i;
	}
}

Calculate sum of M natural numbers starting from N, where N and M should be read from standard input (separated by space). User FOR statement.
Example
Input:
3 4
Output:
18

So my code is: 
#include <stdio.h>

int main(){
int i,n,m,sum;
scanf("%d %d",&n,&m);
sum=n;
for(i=0;i<=m;i++)
    sum=sum+i;
    printf("%d",sum);
}
I set i=0 because I figured since the sum is supposed to start from N itself then that's the way to do it. The problem is though it doesn't work the way it should. What's wrong with my code?  :sigh:  

// blua tigro 1 nov 2017
// sprite 1

#if defined(UNICODE) && !defined(_UNICODE)
    #define _UNICODE
#elif defined(_UNICODE) && !defined(UNICODE)
    #define UNICODE
#endif

#include <tchar.h>
#include <windows.h>
bool key[ 256 ] ;
int winx , winy ;
#define FRAME_TIMER 1
class Sprite
{
public :
  int x , y , w , h ;
  bool visable ;
  BITMAP bmp ;
  Sprite(){;}
  void loadbmpfromfile( HINSTANCE hinstance , TCHAR * file )
  {
    bmp = LoadBitmap( hinstance , _T( file ) ) ;
    w = bmp.bmWidth ;
    h = bmp.bmHeight ;
    visable = true ;
  }
  void show( HDC hdc )
  {
    if ( visable )
    {
    //draw mask whit and [ upper half of bmp ]
    BitBlt( hdc , x , y , w , h/2 , hdc , 0 , 0 , MERGECOPY ) ;
    //draw picture whit or [ lower half of bmp ]
    BitBlt( hdc , x , y , w , h/2 , hdc , 0 , h/2 , MERGEPAINT ) ;
    }
  }
  bool hit( Sprite spr )
  {
    if ( x + w < spr.x ) return false ;
    if ( x > spr.x + spr.w ) return false ;
    if ( y + h < spr.y ) return false ;
    if ( y > spr.y + spr.h ) return false ;
    return true ;
  }
} ;
Sprite player ;
/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

/*  Make the class name into a global variable  */
TCHAR szClassName[ ] = _T("CodeBlocksWindowsApp");

int WINAPI WinMain (HINSTANCE hThisInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR lpszArgument,
                     int nCmdShow)
{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default colour as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           _T("sprite 1"),       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           800,                 /* The programs width */
           600,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           ) ;

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nCmdShow);

    player.loadbmpfromfile(hThisInstance,"player.bmp") ;

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
  PAINTSTRUCT paint ;
  HDC hdc = BeginPaint( hwnd , &paint ) ;
  RECT rect ;

  switch (message)                  /* handle the messages */
  {
    case WM_CREATE :
      player.x = 0 ;
      player.y = 0 ;
      SetTimer( hwnd , FRAME_TIMER , 40 , NULL ) ;
    case WM_KEYDOWN :
      key[ wParam ] = true ;
      switch( wParam )
      {
        case VK_ESCAPE :
          PostQuitMessage( 0 ) ;
          break ;
        default : ;
      }
      break ;
    case WM_KEYUP :
      key[ wParam ] = false ;
      break ;
    case WM_TIMER :
      switch( wParam )
      {
        case FRAME_TIMER :
          if ( key[ VK_UP ] ) player.y-- ;
          if ( key[ VK_DOWN ] ) player.y++ ;
          if ( key[ VK_LEFT ] ) player.x-- ;
          if ( key[ VK_RIGHT ] ) player.x++ ;

          if ( player.y > winy ) player.y = 0 ;
          if ( player.y < 0 ) player.y = winy ;
          if ( player.x > winx ) player.x = 0 ;
          if ( player.x < 0 ) player.x = winx ;
          InvalidateRect( hwnd , NULL , true ) ;
        break ;
        default : ;
      }
      break ;
    case WM_PAINT :
      GetClientRect( hwnd , &rect ) ;
      winx = rect.right ;
      winy = rect.bottom ;

      player.show( hdc ) ;

      EndPaint( hwnd , &paint ) ;
    case WM_DESTROY :
      PostQuitMessage( 0 ) ;       /* send a WM_QUIT to the message queue */
      break;
    default:                      /* for messages that we don't deal with */
      return DefWindowProc (hwnd, message, wParam, lParam);
  }
  return 0 ;
}