import com.google.common.base.Charsets;
import com.google.common.hash.Hashing;
import java.text.MessageFormat;
import com.google.common.base.CaseFormat;

public class Main {
    private static String camelCaseToUpperCaseSeparatedByUnderscore(String s) {
    	return CaseFormat.UPPER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, s);
	}
    public static void main(String[] args) {
        System.out.println(camelCaseToUpperCaseSeparatedByUnderscore("CamelCase"));
    }
}