How to crack IAS

It is generally believed that UPSC Examination is the toughest examination in the world .

But the question is what defines the toughness of examination ?

Toughness is defined by no. of candidates who cleared divided by no. of candidates who applied for UPSC.

And the probability of cracking IAS is 0.01% .

But if one wants to crack such examination he doesn't need to work hard rather he need to work Smartly and I mean it .