import java.util.Arrays;
import java.util.stream.Collectors;
class Main {
public static void main(String[] args) {
Character[] chars = {'a', 'b', 'c', 'd', 'e', 'f', 'g'};
String str = Arrays.stream(chars)
.map(String::valueOf)
.collect(Collectors.joining());
System.out.println(str);
}
}
/*
run:
abcdefg
*/