import math
import sys
input = sys.stdin.read

def max_beautiful_gcd(arr):
    if len(arr) == 1:
        return arr[0]  # If there's only one element, its value is the max GCD
    
    arr.sort()  # Sort the array
    gcd_diff = arr[1] - arr[0]  # Start with the first difference
    
    for i in range(2, len(arr)):
        gcd_diff = math.gcd(gcd_diff, arr[i] - arr[i - 1])
        
    return gcd_diff

# Input reading
data = input().split()
n = int(data[0])
arr = list(map(int, data[1:]))

# Output the result
print(max_beautiful_gcd(arr))