2 shunfurh shunfurh 于 2017.09.16 17:32 提问

Geek's Collection

The word geek is a slang term, with different meanings ranging from "a computer expert or enthusiast" to "a carnival performer who performs sensationally morbid or disgusting acts", with a general pejorative meaning of "a peculiar or otherwise dislikable person, especially one who is perceived to be overly intellectual".

The definition of geek has changed considerably over time, and there is no longer a definitive meaning. The terms nerd, gimp, dweeb, dork, spod and gump have similar meanings as geek, but many choose to identify different connotations among these terms, although the differences are disputed. In a 2007 interview on The Colbert Report, Richard Clarke said the difference between nerds and geeks is "geeks get it done." Julie Smith defined a geek as "a bright young man turned inward, poorly socialized, who felt so little kinship with his own planet that he routinely traveled to the ones invented by his favorite authors, who thought of that secret, dreamy place his computer took him to as cyberspace somewhere exciting, a place more real than his own life, a land he could conquer, not a drab teenager's room in his parents' house."The definition of geek has changed considerably over time, and there is no longer a definitive meaning. The terms nerd, gimp, dweeb, dork, spod and gump have similar meanings as geek, but many choose to identify different connotations among these terms, although the differences are disputed. In a 2007 interview on The Colbert Report, Richard Clarke said the difference between nerds and geeks is "geeks get it done." Julie Smith defined a geek as "a bright young man turned inward, poorly socialized, who felt so little kinship with his own planet that he routinely traveled to the ones invented by his favorite authors, who thought of that secret, dreamy place his computer took him to as cyberspace somewhere exciting, a place more real than his own life, a land he could conquer, not a drab teenager's room in his parents' house."

The biggest geek in the world named Alice, she is major in many subject. One day she come to a new planet named wonderland and she find a way to entertain herself by copy herself again and again, she give the cloning the name as Alice1, Alice2, Alice3... Every Alice like collect things in wonderland, recently, the true Alice want to calculate how many collections did her cloning have.

The number of collections that each cloning have is (1+1/2+1/3+1/4+...+1/n-ln n)*her special number (n tends to infinity), the defination of special number is as follow, for Alice1, her special number is a, for Alice2, her special number is a(a-1)/(1*2), for Alice3, her special number is a(a-1)(a-2)/(1*2*3)... and there are endless cloning Alice. Your task is to help true Alice calculate how many collections did her cloning have.

Input

This problem contains multiple test cases. Each case contains only one line with a float number a. (-1 < a < 0 or a > 0)

Output

Print exactly one line with the number of total collections, you should output it in scientific notation and retained thirteen significant figures. Because the wonderland is an amazing place so that the number of the collection can be negative number.

Sample Input

-0.5
100
Sample Output

-1.690625540426e-01
7.317077840736e+29

1个回答

devmiao
devmiao   Ds   Rxr 2017.09.17 00:51
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