# writer解

n, k = map(int, input().split())
a = list(map(int, input().split()))
a.sort(reverse=1)

ans = 0
for i in range(1 << (n - 1)):
    kk = k
    for j in range(n-1):
        if i & (1 << j):
            kk %= a[j]
    kk %= a[n-1]
    ans = max(ans, kk)
print(ans)