Morris' Blog 我在摸索我存在的意義、生命的意義、內涵及價值。 沒有真正神手般的厲害，套用模式是大部分的情況。 沒那麼厲害的我存在的意義為何，襯托出神的存在？ 有時候不能怪別人不給我機會，我已經開始省思， 為什麼我沒有給別人機會的原因，而是全要靠別人。 有時候我認為我與眾不同，那是因為我做不到很多人能辦到的事情。 我聽不到、玩不起來、說得不夠明瞭、理解得不夠多， 我缺少的語文能力，就是一切一切無能的判定。 為此，我不曉得能做些對別人有幫助的事情。 我知道我自己是個不服輸的性格，但現在我不得不認輸。 我沒有能力，因此我必須認輸。 我到底來這世界作什麼？處處充滿不確定性， 而我總是無法出類拔萃，想當個一般人似乎也回不了頭了。 越強大的挑戰需要越強力的支持，而我的支持是什麼？ 最近嘗試與人談話，但都是失敗的結局，沒人能接受， 不需要言語，不需要溝通，一切所想都表達不出來。

49愛的鼓勵 6訂閱站台

Problem A

Strange Planet

As you know, there are many strange planets in the universe. Dara and Sara are living in one of these strange planets with an unusual coordinate system. This Planet is like a grid having unit-sized cells with the houses considered as points placed in the center of cells. The cells are assigned a unique number as shown in figure 1.

Figure 1. The Strange Planet

Recently, Dara and Sara have become familiar with the well-known Cartesian coordinate system based on X and Y axes, and would like to know the Euclidian distance between their houses. Unfortunately, they don’t know how to calculate this distance. So, they need your help to calculate it. You may assume that the cell with number 0 is located at the origin (with coordinate (0, 0)) of the Cartesian coordinate system.

The Input

Input file consists of many test-cases. Each test-case consists of two integers  indicating the cell numbers that contain their houses. The input will be terminated with a line containing   two -1s.

The Output

For each test-case, print the Euclidian distance between the houses of Dara and Sara rounded to two digits after the fraction point.

Sample Input

2 7

29 32

-1 -1

Sample Output

1.00

4.24