题目描述

(Distance Between Points) Write function distance that calculates the distance between two points (x1, y1) and (x2, y2). All numbers and return values should be of type double.


输入格式

The input consists of n (0<n<100) samples.
Each sample consists of two lines.
Each line of the same sample consists of doubles x, y (range from 0 to 100).
The last line of input consists of Int(-1).


输出格式

The decimal precision of output is 1.


样例数据

输入

1 1
1 0
1 1
0 0
0 1
0 0
-1

输出

1.0
1.4
1.0

备注


操作

评测记录

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信息

时间限制: 1s
内存限制: 128MB
评测模式: Normal

题解