def kotanchek(data):
 return (exp((- ((data[0] - 1) ** 2))) / (3.2 + ((data[1] - 2.5) ** 2)))

def kotanchek ( data ) : return ( exp ( ( - ( ( data [ 0 ] - 1 ) ** 2 ) ) ) / ( 3.2 + ( ( data [ 1 ] - 2.5 ) ** 2 ) ) )
kotanchek benchmark function .