#include<cstdio>
using namespace std;
int main(){
	long a,ans=0;
	char c;
	scanf("%ld",&a);
	ans+=a;
	while(scanf("%c%ld",&c,&a)!=EOF){
		if(c=='-')ans-=a;
		else ans+=a;
	}
	printf("%ld",ans);
	return 0;
}

求大神指教