#include <bits/stdc++.h>

#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;
using lint=long long;

int main(){
	string a,b; cin>>a>>b;

	string s=a+"+"+b;
	int n=s.length();
	lint ans=0,num=0;
	int sgn=1;
	rep(i,n+1){
		if(i==n || s[i]=='+' || s[i]=='-'){
			ans+=sgn*num;
			num=0;
			if(i<n){
				if(i==0 || isdigit(s[i-1])) sgn=1;
				if(s[i]=='-') sgn*=-1;
			}
		}
		else{
			num=10*num+(s[i]-'0');
		}
	}
	printf("%lld\n",ans);

	return 0;
}