// Problem: P4566 [CTSC2018] 青蕈领主
// Contest: Luogu
// URL: https://www.luogu.com.cn/problem/P4566
// Memory Limit: 500 MB
// Time Limit: 3000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define pb emplace_back
#define fst first
#define scd second
#define mkp make_pair
#define mems(a, x) memset((a), (x), sizeof(a))

using namespace std;
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
typedef long double ldb;
typedef pair<ll, ll> pii;
typedef vector<ll> poly;

const int maxn = 500100;
const ll mod = 998244353, G = 3;

inline ll qpow(ll b, ll p) {
	ll res = 1;
	while (p) {
		if (p & 1) {
			res = res * b % mod;
		}
		b = b * b % mod;
		p >>= 1;
	}
	return res;
}

int r[maxn];

inline poly NTT(poly a, int op) {
	int n = (int)a.size();
	for (int i = 0; i < n; ++i) {
		if (i < r[i]) {
			swap(a[i], a[r[i]]);
		}
	}
	for (int k = 1; k < n; k <<= 1) {
		ll wn = qpow(op == 1 ? G : qpow(G, mod - 2), (mod - 1) / (k << 1));
		vector<ll> pw(k);
		pw[0] = 1;
		for (int i = 1; i < k; ++i) {
			pw[i] = pw[i - 1] * wn % mod;
		}
		for (int i = 0; i < n; i += (k << 1)) {
			for (int j = 0; j < k; ++j) {
				ll x = a[i + j], y = pw[j] * a[i + j + k] % mod;
				a[i + j] = (x + y) % mod;
				a[i + j + k] = (x - y + mod) % mod;
			}
		}
	}
	if (op == -1) {
		ll inv = qpow(n, mod - 2);
		for (int i = 0; i < n; ++i) {
			a[i] = a[i] * inv % mod;
		}
	}
	return a;
}

inline poly operator * (poly a, poly b) {
	a = NTT(a, 1);
	b = NTT(b, 1);
	int n = (int)a.size();
	for (int i = 0; i < n; ++i) {
		a[i] = a[i] * b[i] % mod;
	}
	a = NTT(a, -1);
	return a;
}

inline poly mul(poly a, poly b) {
	int n = (int)a.size() - 1, m = (int)b.size() - 1, k = 0;
	while ((1 << k) <= n + m + 1) {
		++k;
	}
	for (int i = 1; i < (1 << k); ++i) {
		r[i] = (r[i >> 1] >> 1) | ((i & 1) << (k - 1));
	}
	poly A(1 << k), B(1 << k);
	for (int i = 0; i <= n; ++i) {
		A[i] = a[i];
	}
	for (int i = 0; i <= m; ++i) {
		B[i] = b[i];
	}
	poly res = A * B;
	res.resize(n + m + 1);
	return res;
}

ll n, a[maxn], f[maxn], ans;

void cdq(int l, int r) {
	if (l == r) {
		if (l > 1) {
			f[l] = (f[l] + (3 - l + mod) * f[l - 1]) % mod;
		}
		return;
	}
	int mid = (l + r) >> 1;
	cdq(l, mid);
	if (l == 1) {
		poly A(mid + 1), B(mid + 1);
		for (int i = l; i <= mid; ++i) {
			A[i] = f[i] * (i - 1) % mod;
			B[i] = f[i];
		}
		poly res = mul(A, B);
		for (int i = mid + 1; i <= r; ++i) {
			f[i] = (f[i] + res[i]) % mod;
		}
	} else {
		poly A(mid - l + 1), B(r - l + 1);
		for (int i = l; i <= mid; ++i) {
			A[i - l] = f[i] * (i - 1) % mod;
		}
		for (int i = 1; i <= r - l; ++i) {
			B[i] = f[i];
		}
		poly res = mul(A, B);
		for (int i = mid + 1; i <= r; ++i) {
			f[i] = (f[i] + res[i - l]) % mod;
		}
		A = poly(mid - l + 1);
		B = poly(r - l + 1);
		for (int i = l; i <= mid; ++i) {
			A[i - l] = f[i];
		}
		for (int i = 1; i <= r - l; ++i) {
			B[i] = f[i] * (i - 1) % mod;
		}
		res = mul(A, B);
		for (int i = mid + 1; i <= r; ++i) {
			f[i] = (f[i] + res[i - l]) % mod;
		}
	}
	cdq(mid + 1, r);
}

inline void init() {
	f[0] = 1;
	f[1] = 2;
	cdq(1, n - 1);
}

void dfs(int l, int r) {
	if (l == r) {
		return;
	}
	if (a[r] != l) {
		ans = 0;
		return;
	}
	int j = r, k = 0;
	for (int i = r - 1; i >= l; --i) {
		if (i + 1 == j) {
			j = a[i];
			dfs(j, i);
			++k;
		} else if (a[i] < j) {
			ans = 0;
		}
	}
	ans = ans * f[k] % mod;
}

void solve() {
	for (int i = 1; i <= n; ++i) {
		scanf("%lld", &a[i]);
		a[i] = i - a[i] + 1;
	}
	ans = 1;
	dfs(1, n);
	printf("%lld\n", ans);
}

int main() {
	int T = 1;
	scanf("%d%lld", &T, &n);
	init();
	while (T--) {
		solve();
	}
	return 0;
}