#include <iostream>
#include <sstream>
#include <math.h>
#include <stack>
#include <set>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <vector>
using namespace std;

#define INF (1 << 30)
#define INFLL (1LL << 60)

int sstoi(string a){
	int n = 0;
	bool flag = 0;
	if(a[0] == '-'){
		flag = 1;
		a.erase(0,1);
	}else if(a[0] == '+'){
		a.erase(0,1);
	}

	for(int i = 0;i < a.size();i++){
		n = n*10;
		n += a[i] - '0';
	}
	if(flag) n = -n;
	return n;
}

int main() {
	bool hugo;
	string str;
	cin >> str;
	string a = "";
	int n,m;
	a += str[0];
	for(int i = 1;i < str.size();i++){
		if(str[i] >= '0' && str[i] <= '9') {
			a += str[i];
		}else{
			if(str[i] == '-') hugo = 1;
			else hugo = 0;
			n = sstoi(a);
			a = "";
			a += str[i+1];
			i++;
		}
	}
	m = sstoi(a);
	if(hugo) cout << n+m << endl;
	else cout << n-m << endl;
	return 0;
}