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

char x;
long long a = 0,b = 0,c = 0,flag = 0,f = 1;//flag代表未知数所在位置 
int main()
{
	x = getchar();
	while(x != '+' && x != '-')
	{
		if(x != '?')
		{
			if(x == ' ')
			{
				x = getchar();
				continue;
			}
			a = a * 10 + (x - '0');
		}
		else flag = 1;
		x = getchar();
	}
	if(x == '-') f = 2;//1:+    2:-
	x = getchar();
	while(x != '=')
	{
		if(x != '?')
		{
			if(x == ' ')
			{
				x = getchar();
				continue;
			}
			b = b * 10 + (x - '0');
		}
		else flag = 2;
		x = getchar();
	}
	x= getchar();
	while(x != '\n')
	{
		if(x != '?')
		{
			if(x == ' ')
			{
				x = getchar();
				continue;
			}
			c = c * 10 + (x - '0');
		}
		else flag = 3;
		x = getchar();
	}
	if(f == 1)
	{
		if(flag == 1) cout<<c - b;
		if(flag == 2) cout<<c - a;
		if(flag == 3) cout<<a + b;
	}
	if(f == 2)
	{
		if(flag == 1) cout<<b + c;
		if(flag == 2) cout<<a - c;
		if(flag == 3) cout<<a - b;
	}
	return 0;
}

rt 大佬们帮个忙吧