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Equation for the 5-th class!

The equation for the fifth grader is a line of length 5 symbols. The second symbol in the line is either a sign '+' (plus) or '-' (minus), the forth symbol is a sign '=' (equals to). Amonng the first, third and fifth symbol exactly two are digits in the range from 0 to 9, and one is a letter x that is a variable.

Write a program to solve the given equation with respect to x.

Input

One line with the given equation.

Output

Print one number - the value of x.

Time limit 1 second
Memory limit 128 MiB
Input example #1
x+5=7
Output example #1
2
Input example #2
3-x=9
Output example #2
-6
Source 2015 ACM Ukraine, First Stage, April 25