#include <bits/stdc++.h>
using namespace std;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

#include <atcoder/dsu>

int main() {
  int N, M;
  cin >> N >> M;

  vector<set<int>> l(N), r(N);
  vector<mint> a(N);
  for (int i = 0; i < M; i++) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    l[v].insert(u);
    r[u].insert(v);
  }

  vector<mint> dp(N, 1);
  atcoder::dsu dsu(N);
  // invariant: true dp[v] = dp[v] + sum_{v in r[u]} a[u]
  for (int i = 0; i < N; i++) {
    int x = i;
    for (int j : l[i]) {
      int y = dsu.leader(j);
      if (x == y)
        continue;
      if (r[y].erase(i))
        dp[i] += a[y];
      dsu.merge(x, y);
      if (dsu.leader(i) == y)
        swap(x, y);
      if (r[x].size() > r[y].size())
        swap(r[x], r[y]), swap(a[x], a[y]);
      for (int k : r[y]) {
        dp[k] += a[y];
        if (r[x].insert(k).second)
          dp[k] -= a[x];
      }
      r[y].clear();
    }
    a[x] += dp[i];
  }

  cout << accumulate(dp.begin(), dp.end(), mint(0)).val();
}