#include <bits/stdc++.h>
using namespace std;
string a;
string b;
int g;
int d,s;
int ans;
int main()
{
	getline(cin,a);
	for(int i=0;i<a.size();i++)
	{
		if(a[i] != ' ') 
			b+=a[i];
	}
	/*------------------------*/
	for(int i=0;i<a.size();i++)
	{
		if(b[i] == '+') 
			g=1;
	}
	for(int i=0;i<a.size();i++)
	{
		if(b[i] == '-') 
			g=2;
	}
	/*------------------------*/
	if(g == 1)//+
	{
		if(b[0] == '?') d=1;
		if(b[2] == '?') d=2;
		if(b[4] == '?') d=3;
	}
	if(g == 2)//-
	{
		if(b[0] == '?') s=1;
		if(b[2] == '?') s=2;
		if(b[4] == '?') s=3;
	}
	/*------------------------*/	
	if(d == 1) 
		ans=b[4]-b[2];
	if(d == 2) 
		ans=b[4]-b[0];
	if(d == 3) 
		ans=b[0]+b[2];
	if(s == 1) 
		ans=b[2]+b[4];
	if(s == 2) 
		ans=b[0]-b[4];
	if(s == 3) 
		ans=b[0]-b[2];
	/*------------------------*/	
	cout << ans;		
	return 0;
}