N,K=map(int,input().split())
A=sorted(map(int,input().split()),reverse=True)
MIN=min(A)
ANS=0

for i in range(1<<(N-1)):
    X=K
    for j in range(N-1):
        if i & (1<<j)!=0:
            X%=A[j]
    ANS=max(ANS,X%MIN)

print(ANS)