// In the name of God
// Hope is last to die
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define pb push_back
#define int long long
#define S second
#define F first
#define mp make_pair
#define smax(x, y) (x) = max((x), (y))
#define smin(x, y) (x) = min((x), (y))
#define all(x) (x).begin(), (x).end()
#define len(x) ((int)(x).size())
const int maxn = 11;
const int inf = 1e9 + 7, mod = 998244353;
int n, m, in[maxn], deg[maxn];
vector<int> adj[maxn], g[maxn];
int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
set<int> st;
int32_t main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m;
for(int i = 0; i < m; i++){
int u, v; cin >> u >> v;
adj[u].pb(v);
}
vector<int> A;
do{
for(int i = 0; i < n; i++){
in[a[i]] = i;
deg[i + 1] = 0;
g[i + 1].clear();
}
for(int i = 1; i <= n; i++){
for(auto u: adj[i]){
if(in[i] > in[u]){
g[u].pb(i);
deg[i]++;
}
else{
g[i].pb(u);
deg[u]++;
}
}
}
for(int i = 1; i <= n; i++) if(!deg[i]) st.insert(i);
int x = 0;
while(st.size()){
int v = (*st.begin());
x *= 10;
x += v - 1;
st.erase(st.begin());
for(auto u: g[v]){
deg[u]--;
if(!deg[u]) st.insert(u);
}
}
A.pb(x);
} while (next_permutation(a, a + n));
sort(all(A));
A.resize(unique(all(A)) - A.begin());
ll ans = 0;
for(auto &per: A){
for(int i = 0; i < n; i++){
in[per % 10 + 1] = n - i;
per /= 10;
}
for(int i = 1; i <= n; i++){
for(auto u: adj[i]) if(in[u] < in[i]) ans++;
}
}
cout << ((ans) % mod) << '\n';
return 0;
}
