import java.util.*;
import java.util.regex.*;
import java.lang.*;
 
class Main
{
    static final String[] data = new String[] {
    "This reverts commit c289f6fa1f8642a5caf728ef8ff87afd5718cd99.",
    "This reverts commit c7740a943ec896247ebc5514b6be02710caf3c53.  There should",
    "This reverts 518920b764ee9150781e68217181b24d0712748e commit."
    };
	public static void main (String[] args) throws java.lang.Exception
	{
        Pattern p = Pattern.compile("\\p{Alnum}{40}");
		for (String s : data) {
            Matcher m = p.matcher(s);
    	    if (m.find()) {
                 System.out.println(m.group());   
    	    }
		}
	}
}

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