import java.io.*;
import java.util.*;
public class Polynoom1{
  public static void main(String[] arg) throws IOException{
    BufferedReader lugeja=new BufferedReader(new FileReader("poly1.txt"));
    String rida=lugeja.readLine();
    StringTokenizer stk=new StringTokenizer(rida, "x+-", true);
    int a=Integer.parseInt(stk.nextToken());
    stk.nextToken();
    String tehe=stk.nextToken();
    int b=Integer.parseInt(stk.nextToken());
    int x=Integer.parseInt(lugeja.readLine());
    if(tehe.equals("+")){
      System.out.println(a*x+b);
    }
    if(tehe.equals("-")){
      System.out.println(a*x-b);
    }
  }
}