I can't figure out how to complete this challenge

var europeanCapitals: [String] = []
var asianCapitals: [String] = []
var otherCapitals: [String] = []

let world = [
  "BEL": "Brussels", 
  "LIE": "Vaduz", 
  "BGR": "Sofia", 
  "USA": "Washington D.C.", 
  "MEX": "Mexico City", 
  "BRA": "Brasilia", 
  "IND": "New Delhi", 
  "VNM": "Hanoi"]

for (key, value) in world {
    // Enter your code below
    switch world {
      case "BEL", "LIE", "BGR": europeanCapitals.append("Bruseels", "Vaduz", "Sofia")
      case "IND", "VNM": asianCapitals.append("New Delhi", "Hanoi")
      case "USA", "MEX", "BRA": otherCapitals.append("Washington D.C.", "Mexico City", "Brasilia")
      default: print("You might want to check that city")
    // End code
}