MOD = 998244353
N,M,K = map(int,input().split())
A = sorted(list(map(int,input().split())))
C = {}
cnt = 1
for i in range(1,M):
    if A[i-1]==A[i]:
        cnt += 1
    else:
        C[A[i-1]] = cnt
        cnt = 1
C[A[-1]] = cnt
D = {i:0 for i in range(1,N+1)}
for a in C:
    for i in range(a,N+1,a):
        D[i] += C[a]
ans = 0
for i in range(1,N+1):
    p = pow(1-D[i]*pow(M,MOD-2,MOD)%MOD,K,MOD)
    ans = (ans+p)%MOD
print((N-ans)%MOD)