import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class Main_yukicoder222 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String xopy = sc.next();

        String regex = "([+-]?\\d+)([+-])([+-]?\\d+)";
        Pattern p = Pattern.compile(regex);
        
        Matcher m = p.matcher(xopy);
        if (m.find()) {
        	int x = Integer.parseInt(m.group(1));
        	String op = m.group(2);
        	int y = Integer.parseInt(m.group(3));
        	
        	if (op.equals("+")) {
        		System.out.println(x - y);
        	} else {
        		System.out.println(x + y);
        	}
        } else {
        	System.out.println("NG");
        }
        
        sc.close();
    }
}