import sys
input = sys.stdin.readline
MOD = 998244353
N, M = map(int, input().split())
A = list(map(int, input().split()))
bk = 0
cnt = 0
for i in range(N):
    a = A[i]
    if a==1:
        if bk==0:
            cnt += 1
    bk = a
dp = [[0 for _ in range(N+1)] for _ in range(M+1)]
dp[0][cnt] = 1
for i in range(M):
    for j in range(N+1):
        if dp[i][j]==0:
            continue
        if j>=1:
            dp[i+1][j-1] += dp[i][j] * (j*2*(j*2-1)//2) % MOD
            dp[i+1][j-1] %= MOD
        if j+1<=N:
            dp[i+1][j+1] += dp[i][j] * ((N+1-j*2)*(N-j*2)//2) % MOD
            dp[i+1][j+1] %= MOD
        dp[i+1][j] += dp[i][j] * (j*2*(N+1-j*2)) % MOD
        dp[i+1][j] %= MOD
    #print(dp)
print(dp[M][0])