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;
}
}