def gen_query(n, m, x, d):
    queries = []
    for k in range(m):
        i = (x // (n-1))
        j = (x % (n-1))
        if i > j:
            i, j = j, i
        else:
            j += 1
        x = (x+d) % (n * (n-1))
        queries.append((i, j))
    return queries

def lcp(a,b):
    size_a =  len(a)
    size_b =  len(b)
    size = min(size_a, size_b)
    for i in range(size):
        if a[i] != b[i]:
            return i
    return size


def main():
    n = int(input())
    s = []
    for i in range(n):
        s.append(input().strip())
    m, x, d = map(int, input().split())
    query = gen_query(n, m, x, d)
    total = 0
    for i, j in query:
        total += lcp(s[i], s[j])
    print(total)

if __name__ == '__main__':
    main()