Import the anscombe dataset using the following commands:

import seaborn as sns

ans $=$ sns$.$load$\_$dataset$(\text{'}$anscombe$\text{'})$

Transform this DataFrame into four separate DataFrames: ans$1,$ ans$2,$ ans$3$ and ans$4$ based on their value in the DataSet column. Consider the products of the x and y values in each of these four DataFrames and find which of the four sets of products has the smallest standard deviation. What is that standard deviation rounded down to the nearest integer?