#include <bits/stdc++.h>
#ifdef DEBUG
#include "debug.hpp"
#endif
using namespace std;
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define traverse(c, it) for(auto it = (c).begin(); it != (c).end(); ++it)
#define rep(i, N) for(int i = 0; i < (N); ++i)
#define rrep(i, N) for(int i = (N) - 1; i >= 0; --i)
#define rep1(i, N) for(int i = 1; i <= (N); ++i)
#define rep2(i, s, e) for(int i = (s); i <= (e); ++i)
#ifdef DEBUG
#define debug(x...) { \
++dbg::depth; \
string dbg_vals = dbg::to_string(x); \
--dbg::depth; \
dbg::fprint(__func__, __LINE__, #x, dbg_vals); \
}
#define light_debug(x) { \
dbg::light = true; \
dbg::dout << __func__ << ":" << __LINE__; \
dbg::dout << " " << #x << " = " << x << endl; \
dbg::light = false; \
}
#else
#define debug(x...) 42
#define light_debug(x) 42
#endif
using ll = long long;
template<typename T>
inline T& ckmin(T& a, T b) { return a = a > b ? b : a; }
template<typename T>
inline T& ckmax(T& a, T b) { return a = a < b ? b : a; }
constexpr int mod{998244353};
array<int, 1 << 18> popcnt;
array<int, 1 << 18> lg;
pair<int, int> solve_for(const vector<int>& adj) {
const int n{int(adj.size())};
vector<bool> is_independent(1 << n, true);
rep1(mask, (1 << n) - 1) {
rep(i, n)
if((mask & (1 << i)) && (adj[i] & mask) != 0) {
is_independent[mask] = false;
break;
}
}
vector<long long> dp_s(1 << n), dp_c(1 << n); dp_c[0] = 1;
vector<int> partial_cost(1 << n);
int j, sources;
long long t_s, t_c;
rep1(mask, (1 << n) - 1) {
for(sources = mask & (mask - 1); ; sources = (sources - 1) & mask) {
sources = mask - sources;
if(is_independent[sources]) {
j = lg[sources];
partial_cost[sources] =
partial_cost[sources - (1 << j)] + popcnt[adj[j] & mask];
t_c = dp_c[mask ^ sources];
t_s = dp_s[mask ^ sources] +
dp_c[mask ^ sources] * partial_cost[sources] % mod;
if(popcnt[sources] & 1)
dp_s[mask] += t_s, dp_c[mask] += t_c;
else
dp_s[mask] -= t_s, dp_c[mask] -= t_c;
}
sources = mask - sources;
if(sources == 0) break;
}
dp_c[mask] %= mod;
dp_s[mask] %= mod;
}
if(dp_s.back() < 0) dp_s.back() += mod;
if(dp_c.back() < 0) dp_c.back() += mod;
return make_pair(int(dp_c.back()), int(dp_s.back()));
}
vector<int> generate_adj(const vector<int>& adj, int mask) {
vector<int> adj2(popcnt[mask]);
vector<int> v;
rep(i, int(adj.size())) if(mask & (1 << i)) v.push_back(i);
rep(i, popcnt[mask]) rep(j, popcnt[mask])
if(adj[v[i]] & (1 << v[j]))
adj2[i] |= 1 << j;
return adj2;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
rep(i, 1 << 18) popcnt[i] = __builtin_popcount(i);
rep(i, 1 << 18) lg[i] = __lg(i);
int n, m; cin >> n >> m;
vector<int> adj(n);
rep(i, m) {
int u, v; cin >> u >> v; --u, --v;
adj[u] |= 1 << v;
}
int vis{};
long long p{1}, ans{};
auto update_component = [&](int v) {
int mask{};
stack<int> s;
s.push(v); mask |= 1 << v;
while(!s.empty()) {
int a = s.top(); s.pop();
rep(u, n) {
if(mask & (1 << u)) continue;
if((adj[u] & (1 << a)) || (adj[a] & (1 << u)))
mask |= 1 << u, s.push(u);
}
}
int cnt, sum;
tie(cnt, sum) = solve_for(generate_adj(adj, mask));
ans = (ans * cnt % mod + p * sum % mod) % mod;
p = (p * cnt) % mod;
vis |= mask;
};
rep(i, n)
if(!(vis & (1 << i)))
update_component(i);
cout << ans << '\n';
#ifdef DEBUG
dbg::dout << "\nExecution time: "
<< clock() * 1000 / CLOCKS_PER_SEC
<< "ms" << endl;
#endif
return 0;
}
