Problem:
Score : 100 points

Problem Statement

Joisino wants to evaluate the formula "A op B".
Here, A and B are integers, and the binary operator op is either + or -.
Your task is to evaluate the formula instead of her.

Constraints

1≦A,B≦10^9

op is either + or -.

Input

The input is given from Standard Input in the following format:

A op B

Output

Evaluate the formula and print the result.

Sample Input 1

1 + 2

Sample Output 1

3

Since 1 + 2 = 3, the output should be 3.

Sample Input 2

5 - 7

Sample Output 2

-2

Solution in Ruby (2.3.3) (judge verdict: Runtime Error)

N = gets.chomp.to_i
A = gets.chomp.split.map{|i| i.to_i}
res = N.times.to_a.permutation.map{|i|i.to_a}.select do |arr|
  r = true
  arr.each_with_index {|v, i|
    left = i
    right = N - 1 - i
    abs = (left - right).abs
    r = false if A[v] != abs
    break unless r
  }
  r
end
p res.length