#! ruby
# yukicoder My Practice
# author: Leonardone @ NEETSDKASU

x = gets.to_i

n = 10 ** 6

2.upto(n) do |i|
    ii = i * i
    loop {
        d, m = x.divmod ii
        break if m > 0
        x = d
    }
end
    
puts x