import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] v = sc.nextLine().split("\\+");
        // System.out.println(Arrays.toString(v));
        int i = 0;
        for(String s:v) {
            i+= calc(s);

        }
        System.out.println(i);
    }
    public static int calc(String s) {
        //13-14
        char[] ch = s.toCharArray();

        int i = 0;
        int l=0;int r=0;
        while (i<ch.length && ch[i]!='-') {

            l= (ch[i]-'0')+ l*10;


            ++i;
        }

        while (++i<ch.length) {
            r = (ch[i]-'0')  + r*10;
        }
        // System.out.println(l+" - >"+r);
        return l-r;

    }
}