import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class Main {
public static void main(String[] argv) {
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
System.out.println(numbers.stream().map(number -> String.valueOf(number))
.collect(Collectors.joining(", ")));
}
}