Submit solution

Points:
3

Time limit:
1.0s

Memory limit:
32M

Problem type

Allowed languages

Ada, Assembly, Awk, Brain****, C, C#, C++, COBOL, ~~CommonLisp~~, D, Dart, F#, Forth, Fortran, Go, ~~Groovy~~, Haskell, Intercal, Java, JS, Kotlin, Lisp, Lua, ~~Nim~~, ~~ObjC~~, OCaml, ~~Octave~~, Pascal, Perl, PHP, Pike, Prolog, Python, Racket, Ruby, Rust, Scala, Scheme, Sed, Swift, TCL, Text, Turing, VB, Zig

Mirko has chosen four integers which form an arithmetic progression. In other words, when the four
numbers are sorted, then the difference between each pair of **adjacent** elements is **constant**.

As has become usual, Mirko lost one of the numbers and also is not sure whether the remaining three are in the correct (sorted) order.

Write a program that, given the three remaining numbers, finds the fourth number.

#### Input Specification

The input contains integers between and on a single line, separated by single spaces.

Note: the input data will guarantee that a solution, although not necessarily unique, will always exist.

#### Output Specification

Output any number which could have been the fourth number in the sequence.

#### Sample Input 1

`4 6 8`

#### Sample Output 1

`10`

#### Sample Input 2

`10 1 4`

#### Sample Output 2

`7`

## Comments