Competitions

# Formatting

# 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**.

Input example #1

x+5=7

Output example #1

2

Input example #2

3-x=9

Output example #2

-6