INF=10**18;
def op(a,b):
    c=[[-INF]*len(b[0])for i in range(len(a))]
    for i in range(len(a)):
        for j in range(len(b[0])):
            c[i][j]=max([min(a[i][k],b[k][j])for k in range(len(b))])
    return c
def e(K):
    a=[[-INF]*K for i in range(K)]
    for i in range(K):
        a[i][i]=INF;
    return a
def my_pow(a,b):
    if b==0:
        return e(len(a))
    if b%2==1:
        return op(my_pow(a,b-1),a)
    c=my_pow(a,b//2);
    return op(c,c)
K,N=map(int,input().split())
assert 1<=K<=100
assert 0<=N<=INF
A=list(map(int,input().split()))
B=list(map(int,input().split()))
for i in A:
    assert -INF<=i<=INF
for i in B:
    assert -INF<=i<=INF
a=[[-INF]for i in range(K)]
b=[[-INF]*K for i in range(K)]
for i in range(K):
    a[i][0]=A[i]
for i in range(K):
    b[K-1][i]=B[i]
for i in range(K-1):
    b[i][i+1]=INF
print(op(my_pow(b,N),a)[0][0])