# Is this an arithmetic progression?

Given 3 numbers

`a`

, `b`

, and `c`

your task is to determine if those 3 numbers could form an arithmetic progression. Print `arithmetic progression`

in case those 3 numbers could be part of an arithmetic progression and `no pattern found`

otherwise.## Definition of an Arithmetic Progression

An arithmetic progression is a sequence of numbers where each term is obtained by adding a

**fixed**number to the previous term. For example, -4, -2, 0, 2, 4 is an arithmetic progression because each term is obtained by adding 2 to the previous term (-4 + 2 = -2, -2 + 2 = 0, and so on).Input | Output |

1
2
3 | arithmetic progression |

1
2
2 | no pattern found |

#### Constraints

Time limit: 1 seconds

Memory limit: 512 MB

Output limit: 1 MB