#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,b)  FOR(i,0,b)
#define X real()
#define Y imag()
#define S second;
#define F first;
#define PB(a) push_back(a)
#define BE(c) c.begin(),c.end()
using namespace std;
typedef long long LL;
typedef pair<int,int> pr;
typedef pair<pr,int> ppr;
typedef priority_queue<pr,vector<pr>,greater<pr> > PQ;
typedef vector<pr> Vpr;
typedef vector<LL> VI;
typedef complex<LL> cld;
typedef vector<cld> Vcld;
const int SIZE=1000010;
const LL INF=1<<30;
int main(){	
	string s;
	int now=0,type=1,pm=1,ans=0;
	cin >> s;
	while(now!=s.size()){
		if(type==1){
			if(s[now]=='-') pm*=-1;
			else pm*=1; 
			if(s[now]!='-' && s[now]!='+')
				type++;
		}
		if(type==2){
			long long x=0;
			while('0'<=s[now] && s[now]<='9'){
				x*=10;
				x+=s[now]-'0';
				now++;
			}
			now--;
			ans+=pm*x;
		}
		else if(type==0){
			if(s[now]=='-') pm=1;
			else pm=-1;
		}
		now++;
		type++;
		type%=3;
	}
	cout << ans << endl;
	return 0;
}