import java.util.regex.*;

class Samp02 {
	public static void main(String[] args){
		Pattern p = Pattern.compile("aba");
		Matcher m = p.matcher("abababa");
		int start = 0;
		while(m.find(start)){
			System.out.printf("%d:%s\n", m.start(), m.group());
			start = m.start() + 1;
		}
	}
}