MOD=998244353
N,M=map(int,input().split())
A=list(map(int,input().split()))
flp=[A[0]]
for i in range(N-1):
    if A[i]==A[i+1]:
        flp.append(0)
    else:
        flp.append(1)
flp.append(A[-1])
dp=[0]*(N+2)
dp[sum(flp)]=1
for i in range(M):
    ndp=[0]*(N+2)
    for j in range(N+2):
        dp[j]%=MOD
        if dp[j]==0:
            continue
        one=j
        zero=N+1-j
        ndp[j]+=one*zero*dp[j]
        if zero>=2:
            ndp[j+2]+=zero*(zero-1)*dp[j]//2
        if one>=2:
            ndp[j-2]+=one*(one-1)*dp[j]//2
    dp=ndp
print(dp[0]%MOD)