N,K = map(int,input().split())
lsA = list(map(int,input().split()))
# bit全探索
lsA.sort(reverse=True)
minA = lsA[-1]
lsA2 = lsA[:-1]
NN = len(lsA2)

ans = 0
for i in range(2**NN):
    ll = []
    for j in range(NN):
        if (i>>j) & 1:
            ll.append(lsA2[j])
    c = K
    for j in range(len(ll)):
        c %= ll[j]
    c%=minA
    ans = max(ans,c)
print(ans)