MOD = 10 ** 9 + 7


def factorials(n, c):
    l = [1]
    for x in range(c + 1, n):
        l.append((l[-1] * x) % MOD)
    return l


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

alph = []
for _ in range(N):
    inp = input().strip()
    alph.append(inp)
alph = sorted(alph)

fac = factorials(len(alph), N - K)

TREE = {}
for ind, init in enumerate(alph):
    tree_ = TREE
    i = 0
    while init[i] in tree_ and isinstance(tree_[init[i]], dict):
        tree_ = tree_[init[i]]
        i += 1
    substr = init[i + 1:-1]
    subtree = {}
    if substr:
        st_ = subtree
        for c in substr:
            st_[c] = {}
            st_ = st_[c]
        st_[init[-1]] = ind
    else:
        subtree = ind
    tree_[init[i]] = subtree


def get_blocks(s):
    tree_ = TREE
    for c in s:
        if isinstance(tree_, dict):
            tree_ = tree_[c]
        else:
            yield tree_
            tree_ = TREE[c]
    yield tree_


inds = list(get_blocks(input().strip()))

index = 0
indexes = list(range(len(alph)))
for j, i in enumerate(inds):
    k = indexes.index(i)
    del indexes[k]
    index += (fac[K - j - 1] * k) % MOD

print(index + 1)