import java.util.StringTokenizer;

/**
 * LongestSubString by karthik
 */
public class LongestSubString {
    public static void main(String[] args) {
        String str = "Java for Geeks";
        StringTokenizer st = new StringTokenizer(str);
        int count = 0;
        String longestString = "";
        while(st.hasMoreTokens()) {
            String lstring = st.nextElement().toString();
            int len = lstring.length();
            if(count < len) {
                count = len;
                longestString = lstring;
            }
        }
        System.out.println("The longest substring in the string : " + longestString);
    }
}