def solve():
    N, M = map(int, input().split())
    A = list(map(int, input().split()))
    Mod = 998244353

    K = A.count(-1)
    if K == 1:
        i = A.index(-1)
        A[i] = (- sum(A[j] for j in range(N) if i != j)) % M

    if -1 not in A:
        if sum(A) % M != 0:
            return 0

        cum = 0
        k = 0
        for a in A:
            cum += a; cum %= M
            if cum == 0:
                k += 1
        return N - k

    left = min(i for i in range(N) if A[i] == -1)
    right = max (i for i in range(N) if A[i] == -1)

    cum = 0
    H = (M - sum(A[i] for i in range(N) if A[i] != -1 and not(left < i < right))) % M
    S = 0

    for i in range(N):
        if i < left:
            cum += A[i]; cum %= M
            if cum == 0:
                S += pow(M, K-1, Mod)
        elif left <= i < right:
            S += pow(M, K-2, Mod)
        else:
            if i == right:
                cum += H
            else:
                cum += A[i]
            cum %= M
            if cum == 0:
                S += pow(M, K-1, Mod)

    return (N * pow(M, K-1, Mod) - S) % Mod

#==================================================
import sys
input=sys.stdin.readline
write=sys.stdout.write

T=int(input())
write("\n".join(map(str, [solve() for _ in range(T)])))