let input =  readLine()?.split(separator: " ")
		  let a = input![0]
		  let b = input![1]
		  print(a)
`

		  let maximumNumberOfLoginAttempts = 10
		  var currentLoginAttempt = 0
		  var x = 0.0, y = 0.0, z = 0.0
`

		  // 这是一个注释
		  
		  /* 这也是一个注释，
		  但是是多行的 */
		  
		  /* 这是第一个多行注释的开头
		  /* 这是第二个被嵌套的多行注释 */
		  这是第一个多行注释的结尾 */
`

		  if let constantName = someOptional {
		      statements
		  }
		  
		  if let actualNumber = Int(possibleNumber) {
		      print("\'\(possibleNumber)\' has an integer value of \(actualNumber)")
		  } else {
		      print("\'\(possibleNumber)\' could not be converted to an integer")
		  }
		  // 输出“'123' has an integer value of 123”
		  
		  if let firstNumber = Int("4"), let secondNumber = Int("42"), firstNumber < secondNumber && secondNumber < 100 {
		      print("\(firstNumber) < \(secondNumber) < 100")
		  }
		  // 输出“4 < 42 < 100”
		  
		  if let firstNumber = Int("4") {
		      if let secondNumber = Int("42") {
		          if firstNumber < secondNumber && secondNumber < 100 {
		              print("\(firstNumber) < \(secondNumber) < 100")
		          }
		      }
		  }
		  // 输出“4 < 42 < 100”
`

		  if let firstNumber = Int("4"), let secondNumber = Int("42"), firstNumber < secondNumber && secondNumber < 100 {
		      print("\(firstNumber) < \(secondNumber) < 100")
		  }
		  // 输出“4 < 42 < 100”
		  
		  if let firstNumber = Int("4") {
		      if let secondNumber = Int("42") {
		          if firstNumber < secondNumber && secondNumber < 100 {
		              print("\(firstNumber) < \(secondNumber) < 100")
		          }
		      }
		  }
		  // 输出“4 < 42 < 100”
`