Problem
Status Ranklist

C语言程序设计教程（第三版）课后习题6.8

Time Limit
1s
Memory Limit
131072KB
Judge Program
Standard
Ratio(Solve/Submit)
85.71%(12/14)
Description:

有一分数序列： 2/1 3/2 5/3 8/5 13/8 21/13...... 求出这个数列的前N项之和，保留两位小数。

Input:

N

Output:

数列前N项和

Sample Input:
10
Sample Output:
16.48
Submit