def next_query(n, x, d):
    i = (x // (n-1))
    j = (x % (n-1))
    if i > j:
        i, j = j, i
    else:
        j += 1
    x = (x+d) % (n * (n-1))
    return i, j, x

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())
    total = 0
    for _ in range(min(m, n*(n+1))):
        i, j, x = next_query(n, x, d)
        total += lcp(s[i], s[j])
        # print(total, lcp(s[i], s[j]))
    if m <= n*(n+1):
        print(total)
        exit()
    
    total *= m // (n*(n+1))
    # print(total)
    for _ in range(m % (n*(n+1))):
        i, j, x = next_query(n, x, d)
        total += lcp(s[i], s[j])
        # print(total, lcp(s[i], s[j]))

    print(total)

if __name__ == '__main__':
    main()