#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 998244353;
const ll LOGN = 18;
const ll INF = 1e15;
const ll MAXN = 2100;
map<vector<int>, int> mp;
ll dp[MAXN], fact[MAXN], inv[MAXN];
ll expo(ll a, ll b) {
ll res = 1;
while (b) {
if (b & 1)
res = (res * a) % MOD;
a = (a * a) % MOD;
b /= 2;
}
return res;
}
ll calc(ll x) {
return (x * (x - 1) / 2) % MOD;
}
ll nCr(ll n, ll r) {
return (fact[n] * inv[r] % MOD) * inv[n-r] % MOD;
}
int main() {
fast
fact[0] = inv[0] = 1;
for (ll i = 1; i < MAXN; i++) {
fact[i] = (fact[i-1] * i) % MOD;
inv[i] = expo(fact[i], MOD - 2);
}
int n, k;
cin >> n >> k;
for (int i = 0; i < n; i++) {
string s;
cin >> s;
vector<int> cnt(26, 0);
for (auto u : s)
cnt[u-'a']++;
mp[cnt]++;
}
vector<int> cnt;
for (auto u : mp)
cnt.push_back(u.s);
dp[0] = 1;
for (auto u : cnt) {
for (int j = k; j >= 0; j--) {
for (int q = u; q >= 1; q--) {
if (j + calc(q) <= k)
dp[j+calc(q)] = (dp[j+calc(q)] + nCr(u, q) * dp[j]) % MOD;
}
}
}
cout << dp[k] << "\n";
}
