Problem:
Greatest Common Divisor

Write a program which finds the greatest common divisor of two natural numbers a and b

Input

a and b are given in a line sparated by a single space.

Output

Output the greatest common divisor of a and b.

Constrants

1 ≤ a, b ≤ 109

Hint

You can use the following observation:

For integers x and y, if x ≥ y, then gcd(x, y) = gcd(y, x%y)

Sample Input 1

54 20

Sample Output 1

2

Sample Input 2

147 105

Sample Output 2

21

Solution in Kotlin (judge verdict: Accepted)

fun main(args: Array<String>) {
    val array = readLine()!!.split(" ").map(String::toInt).toMutableList()
    var x = array[0]
    var y = array[1]
    val newArray = mutableListOf<Int>()

    var count = 1
    while (count != 0) {
        count = x % y
        if (count == 0) newArray.add(y) else newArray.add(count)
        x = y
        y = count
    }
    println(newArray.last())
}