#include <bits/stdc++.h>
using namespace std;

int main(){
	string s;
	cin >> s;
	int math = 1;
	int mid = 1;
	while(s.size() != mid){
		if(s[mid] == '+' or s[mid] == '-') break;
		mid++;
	}
	int a = 0, b = 0;
	for(int i = mid - 1; i >= 0; i--){
		if(s[i] == '-')	a *= -1;
		else if(s[i] == '+') continue;
		else a += int(s[i] - '0') * math;
		math *= 10;
	}
	math = 1;
	for(int i = s.size() - 1; i > mid; i--){
		if(s[i] == '-')	b *= -1;
		else if(s[i] == '+') continue;
		else b += int(s[i] - '0') * math;
		math *= 10;
	}
	if(s[mid] == '+') cout << a - b << endl;
	else cout << a + b << endl;
	return 0;
}