In mathematics and mathematical logic, Boolean algebra is a sub-area of algebra in which the values of the variables are true or false, typically denoted with 1 or 0 respectively. Instead of elementary algebra where the values of the variables are numbers and the main operations are addition and multiplication, the main operations of Boolean algebra are the conjunction (denoted ∧), the disjunction (denoted ∨) and the negation (denoted ¬).

In this mission you should implement some boolean operations:

- **"conjunction"**
denoted x ∧ y, satisfies x ∧ y = 1 if x = y = 1 and x ∧ y = 0 otherwise.

- **"disjunction"**
denoted x ∨ y, satisfies x ∨ y = 0 if x = y = 0 and x ∨ y = 1 otherwise.

- **"implication"** (material implication)
denoted x→y and can be described as ¬ x ∨ y.
If x is true then the value of x → y is taken to be that of y.
But if x is false then the value of y can be ignored; however the operation must return
some truth value and there are only two choices, so the return value is the one that entails less, namely true.

- **"exclusive"** (exclusive or)
denoted x ⊕ y and can be described as (x ∨ y)∧ ¬ (x ∧ y).
It excludes the possibility of both x and y. Defined in terms of arithmetic it is addition mod 2 where 1 + 1 =
0.

- **"equivalence"**
denoted x ≡ y and can be described as ¬ (x ⊕ y).
It's true just when x and y have the same value.

Here you can see the truth table for these operations:

x | y | x∧y | x∨y | x→y | x⊕y | x≡y | -------------------------------------- 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | --------------------------------------

You are given two boolean values **x** and **y** as 1 or 0 and you are given an operation
name as described earlier. You should calculate the value and return it as 1 or 0.

**Input: ** Three arguments. X and Y as 0 or 1. An operation name as a string.

**Output: ** The result as 1 or 0.

**Example:**

boolean(1,...