dem processing

Calculate hill-shade, aspect and slope

// import the country feasture collection
var countries = ee.FeatureCollection('ft:1tdSwUL7MVpOauSgRzqVTOwdfy17KDbw-1d9omPw');
// list with country names
var country_names = ["??"];
// find the countries in the country list
var country = countries.filter(ee.Filter.inList('Country',??));
// Get the geometry of the countries
var region = country.geometry();

var dem = ee.Image("USGS/SRTMGL1_003");
dem = dem.clip(region);
var terrain = ee.Algorithms.Terrain(dem);

print(terrain)

var slope = terrain.select("??")
var aspect = terrain.select("??")
var hillshade = terrain.select("??")

Map.addLayer(dem,{min:??,max:??,palette:"??"},"DEM");
Map.addLayer(slope,{min:??,max:??,palette:"??"},"slope");
Map.addLayer(aspect,{min:??,max:??,palette:"??"},"aspect");
Map.addLayer(hillshade,{min:??,max:??,palette:"??"},"hillshade");