text: 
  def gcd(a,b): 
    
      # base case if a and b are equal  
      if (a == b): 
          return a 
      # if a is greater 
      if (a > b): 
          return gcd(a-b, b) 
            
      return gcd(a, b-a) 
  
  a = 15 
  b = 20
  print('GCD of', a, 'and', b, 'is', gcd(a, b)) 