import java.util.*;
import java.io.*;
class Ideone {
public static String join
(List
<String
> msgs
) { int size = msgs == null ? 0 : msgs.size();
return size == 0 ? "" : size == 1 ? msgs.get(0) : msgs.subList(0, --size).toString().replaceAll("^.|.$", "") + " and " + msgs.get(size);
}
System.
out.
println(join
(null)); System.
out.
println(join
(Arrays.
asList("one",
"two",
"three"))); }
}
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