#!/usr/bin/env perl

# Challenge 261
#
# Task 2: Multiply by Two
# Submitted by: Mohammad Sajid Anwar
#
# You are given an array of integers, @ints and an integer $start..
#
# Write a script to do the followings:
#
# a) Look for $start in the array @ints, if found multiply the number by 2
# b) If not found stop the process otherwise repeat
#
# In the end return the final value.
# Example 1
#
# Input: @ints = (5,3,6,1,12) and $start = 3
# Output: 24
#
# Step 1: 3 is in the array so 3 x 2 = 6
# Step 2: 6 is in the array so 6 x 2 = 12
# Step 3: 12 is in the array so 12 x 2 = 24
#
# 24 is not found in the array so return 24.
#
# Example 2
#
# Input: @ints = (1,2,4,3) and $start = 1
# Output: 8
#
# Step 1: 1 is in the array so 1 x 2 = 2
# Step 2: 2 is in the array so 2 x 2 = 4
# Step 3: 4 is in the array so 4 x 2 = 8
#
# 8 is not found in the array so return 8.
#
# Example 3
#
# Input: @ints = (5,6,7) and $start = 2
# Output: 2
#
# 2 is not found in the array so return 2.

use Modern::Perl;

my($start, @ints) = @ARGV;
say mult_two($start, @ints);

sub mult_two {
    my($n, @ints) = @_;
    while (grep {$_ == $n} @ints) {
        $n *= 2;
    }
    return $n;
}