title: Python While Loop, the and (&) operator is not working
body: <p>I am trying to find the greatest common factor.</p>
  
  <p>I wrote a bad (operation intensive) algorithm that decrements the lower value by one, checks using % to see if it evenly divides both the numerator and denominator, if it does then it exits the program. However, my while loop is not using the and operator, and thus once the numerator is divisible it stops, even though its not the correct answer. </p>
  
  <p>The numbers I am using are 54 and 42, the correct GCD (greatest common denominator) is 6. </p>
  
  <pre><code>#heres a simple algorithm to find the greatest common denominator: 
  
  iterations = 0; #used to calculate number of times while loop is executed
  
  u = 54; v= 42; d = v-1; #u is the numerator, v is the denominator, d is the number decremented by one 
  
  while ((v % d !=0) &amp; (u % d != 0)): #while both numerator AND denominator cannot be evenly divided by the decremented number
   d -= 1 #decrement the number by one
   print d #print the number decremented
   iterations +=1 #add 1 to the count of iterations in while loop
  
  print "the gcd is " +str(d) #should be 6 when the number can evenly divide both
  print "the number of iterations was " +str(iterations) #display times it took algorithm to complete
  </code></pre>
  
  <p>The answer I am getting is 27, which tells me once it reaches 27 and can divide 54/27 evenly, it stops. Any thoughts on how to use an and operator in a while loop in python? </p>
  
  <p>Thanks!</p>