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

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

int main() {
	string s;
	cin >> s;
	int N = s.size();
	vector<ll> d(2), si(2, 1);
	int f = 0, j = 0;
	rep(i, N) {
		if(isdigit(s[i])) {
			if(f == 0) f++;
			d[j] = d[j] * 10 + s[i] - '0';
		}
		else {
			if(f == 0 ) {
				if(s[i] == '-') si[0] *= -1;
			}
			else {
				if(j == 0) {
					j++;
					if(s[i] == '+') si[1] *= -1;
				}
				else {
					if(s[i] == '-') si[1] *= -1;
				}
			}
		}
	}
	cout << si[0] * d[0] + si[1] * d[1] << endl;
}