\begin{array}{c} \color{#db1616}{\texttt{#Khoadang09}} \end{array}

`@`$\texttt{Ruby: }$

`@` Giống i đúc Python thôi)

include Math 
def check_prime(n)
    if n < 2 then return false end
    for i in 2..sqrt(n).to_i 
        if n % i == 0 then return false
        end
    end
    return true 
end
n = gets.chomp.to_i 
if check_prime(n) then
    puts "#{n} is prime"
else 
    puts "#{n} is not prime"
end