n,k = map(int,input().split())
a = list(map(int,input().split()))
a.sort()
nax = 0
# for i in range(n):
#     u = a[:i]
#     crt = k % a[i]
#     for j in range(len(u)):
#         v = a[:j]
#         while v:
#             crt %= st
#
#
#
#     nax = max(nax,crt)
import copy
for i in range(n):
    u = copy.deepcopy(k)
    for j in range(i, -1, -1):
        u %= a[j]
    nax = max(nax, u)

print(nax)