Why it doesn't work here

Question

Only here"Cannot find symbol"
import java.util.*;
public class Program
{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println(Arrays
.stream(scan.nextLine().split(" "))
.map((w)->{
switch (w){
case("10"):
w="ten";
break;
case("9"):
w="nine";
break;
case("8"):
w="eight";
break;
case("7"):
w="seven";
break;
case("6"):
w="six";
break;
case("5"):
w="five";
break;
case("4"):
w="four";
break;
case("3"):
w="three";
break;
case("2"):
w="two";
break;
case("1"):
w="one";
break;
}
return w;
}).collect(Collectors.joining(" ")));
}
}

Answer 1

// add also
import java.util.stream.Collectors;

Answer 2

https://code.sololearn.com/cM7bkNVbQws4

Answer 3

Thx. Hm interesting. I thought that import java.util.*; adds all including stream.Collectors