First Presence of an Opposite Pair X88445


Statement
 

pdf   zip

Write a program that receives on stdin lines containing integers and writes out the first line in which both some number and its opposite appear; the line is to be reported together with the number itself.

Input

The input is a sequence of zero or more lines. Each line cointains zero or more integers, separated by spaces.

Output

Output is the first line of the input in which both some number nn and its opposite −n-n appear, preceded by the non-negative case of the number itself, with ": " (colon-single space) as separator. If several such numbers appear, the earliest-starting pair is to be reported. If there is no such line, the program must write "Not found."

Public test cases

  • Input

    -1 3 -2 -3 1 2
-4 4 -5 5 -6 6

    Output

    1: -1 3 -2 -3 1 2

  • Input

    5 -4 3 -2 1
3 2 1 2 3
2 1 0 1 2
111 -111

    Output

    0: 2 1 0 1 2

  • Input

    9 8 7 6 5
4 3 2 1

    Output

    Not found.

  • Input

    49 38 27 16
101 222 3 -3 222 -101 -222
23 24 -23 -24

    Output

    101: 101 222 3 -3 222 -101 -222
    • Information
    Author
    José Luis Balcázar
    Language
    English
    Official solutions
    Python
    User solutions
    Python