Common Divisor of Array

Write a function that returns the greatest common divisor of all array elements. If the greatest common divisor is 1, return 1.

Examples

gcd([10, 20, 40]) ➞ 10

gcd([1, 2, 3, 100]) ➞ 1

gcd([1024, 192, 2048, 512]) ➞ 64

Notes

• Array elements are always greater than 0.
• There is a minimum of two array elements given.