Dinner

Time Limit: 2s

Memory Limit: 131072KB

Description

Tomorrow, Our institute held a party. Our institute has 100 people.We hold a circle to have dinner evenly. But not any one came to the party. Alice wanted to charge. But he didn't know how many people came. He had two friends, Bob and Caca. So he already knew three positions:(Bob’s, Caca’s and himself). He wanted to know at least how many people came.



Input

Multiple cases, end with EOF.

Each case consists of three lines, each of them contains a pair of numbers: (x, y), the position. All the numbers are in the range of [-200.0, 200.0].



Output

The minimum number of people who came to the party. If impossible, output "NO" in one line

Sample Input

0.0   0.0
1.0   0.0
0.0   1.0

Sample Output

4

Hint

None

Source

None

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