#include<bits/stdc++.h>
using namespace std;
int main(){
    string s;
    char a;
    int ans=0,x=0,i=0;
    cin>>s;
    while(i<s.size()){
        if(!isdigit(s[i])){
            a=s[i];
            i++;
        }while(isdigit(s[i])&&i<s.size()){
            x=10*x+s[i]-48;
            i++;
        }if(a=='+')ans+=x; 
        else if(a=='-')ans-=x; 
        else ans=x;
        x=0;
    }cout<<ans<<endl;
    return 0;
}