import java.util.regex.*;

class Regex {
    public static void main(String args[]) {
        String s1 = "Hello World";
        System.out.println(s1.matches("o")); // false
        System.out.println(s1.matches("^.*o.*$")); // true
        System.out.println(s1.replaceAll("([A-Z])", "O\'$1"));
        s1.toLowerCase();
        String[] splits = s1.split("");
        System.out.println(splits.length);
        for(String s : splits)
            System.out.println("\t" + "|"+s+"|");
    }
}