Swipr issue while X and Y axis distance less than 50

try{
    List<WebElement> el=driver.findElements(xpath);
    System.out.println("No of elements: "+el.size());
    int a,b,c;
    element=(MobileElement)el.get(0);
    int topY = element.getLocation().getY();
    int bottomY = topY + element.getSize().getHeight();
    int centerX = element.getLocation().getX() + (element.getSize().getWidth()/2);
   
    /*if(topY<0){
        element=(MobileElement)el.get(1);
    topY = element.getLocation().getY();
    bottomY = topY + element.getSize().getHeight();
    centerX = element.getLocation().getX() + (element.getSize().getWidth()/2);
    }*/
    if(topY<0)
        topY=50;
    if(bottomY>driver.manage().window().getSize().height)
    bottomY=driver.manage().window().getSize().height-50;
//    System.out.println("topY="+topY);
//    System.out.println("bottomY="+bottomY);
//    System.out.println("centerX="+centerX);
    driver.swipe(centerX, bottomY, centerX, topY, duration);
    if (bottomY-topY<=50){
        bottomY=driver.manage().window().getSize().height-50;
        topY=bottomY-50;
    }   
    driver.swipe(centerX, bottomY, centerX, topY, duration);
       
   
    }catch(Exception e){
        System.out.println("Exception occurred while swipeing up");
    }