import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
 
class Test {
 
	public static void main(String[] args) {
		Pattern p = Pattern.compile("\\[(\\{.*\\})]");
		System.out.println(p.toString()); //debug
		Matcher m = p.matcher("[{po{t[a]}to}];");
		boolean found = m.find();
		if(found)
			System.out.println(m.group(1));
			// expect: {po{t[a]}to}
		else
		{
			System.out.println("no matches found");
			System.out.println(m.toString());
		}
 
	}
 
}
 

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