//cloud mask along with function to add image as layer in the collection
function addImage(img)
{
var id = img.id;
var image = ee.Image(img.id);
Map.addLayer(image);

var cloudBitMask = ee.Number(2).pow(10).int();
var cirrusBitMask = ee.Number(2).pow(11).int();
var qa = image.select('QA60');
Map.addLayer(qa.bitwiseAnd(cloudBitMask).neq(0), {}, 'clouds');
Map.addLayer(qa.bitwiseAnd(cirrusBitMask).neq(0), {}, 'cirrus');

function maskS2clouds(image)
{
var qa = image.select('QA60');
var mask = qa.bitwiseAnd(cloudBitMask).eq(0).and(
         qa.bitwiseAnd(cirrusBitMask).eq(0));
return image.updateMask(mask);
}

var cloudMasked = sentinel.filterBounds(agra).map(maskS2clouds);
var median = cloudMasked.median();
Map.addLayer(median
, {bands: ['B4', 'B3', 'B2'], max: 2000}, 'median');
print(median);
}