#P1920. 成功密码

成功密码

Description

Given a real number xx and a positive integer NN, compute:

i=1Nxii.\sum_{i=1}^{N}\dfrac{x^{i}}{i}.

Input Format

One line containing two numbers x,Nx, N.

Output Format

Output one number representing the answer.

Print the result with 44 decimal places.

1 1
1.0000

Hint

For 30%30\% of the testdata, N106N \le 10^{6}.

For 100%100\% of the testdata, 1N10181 \le N \le 10^{18}, 0<x10 < x \le 1, and xx has at most 44 decimal places.

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