title: What is the point of using max function for two lists?
body: <p>I am reading a code about  kangaroo race;<br>
  It gets an input of x1 v1 and x2 v2. Like shown bleow.<br>
  I want to figure out what is the difference of using max(X,Y) and min(X,Y);<br> where we could make max(x1,x2) and min(x1, x2); <br>
  Please help me to understand it.</p>
  
  <pre><code>x1, v1, x2, v2 = map(int, raw_input().split())
  X = [x1, v1]
  Y = [x2, v2]
  back = min(X, Y)
  fwd = max(X, Y)
  dist = fwd[0] - back[0]
  while back[0] &lt; fwd[0]:
      back[0] += back[1]
      fwd[0] += fwd[1]
      if fwd[0] - back[0] &gt;= dist:
          break
  
  print ["NO", "YES"][back[0] == fwd[0]]
  </code></pre>