求和 - Problem - HNUAHE-OJ

Problem E: 求和

Problem E: 求和

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Time Limit : 1.000 sec Memory Limit : 128 MiB

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Description

输入n的值，求1-1/2+1/3-1/4+...+1/n的和，结果保留5位小数

Input

n的值

Output

计算结果

Sample Input Copy

1
2
3

Sample Output Copy

1.00000
0.50000
0.83333

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