N,K=map(int,input().split())
A=list(map(int,input().split()))

MIN=min(A)
ANS=K%MIN

for a in A:
    ANS=max(ANS,(K%a)%MIN)

import random

for i in range(10**6):
    T=K
    while T>=MIN:
        T%=A[random.randint(0,N-1)]
    ANS=max(ANS,T)

print(ANS)