#include <bits/stdc++.h>
#include <atcoder/all>
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define rep2(i,m,n) for(int (i)=(m);(i)<(n);(i)++)
#define rep2ll(i,m,n) for(ll (i)=(m);(i)<(n);(i)++)
#define ALL(obj) (obj).begin(), (obj).end()
#define rALL(obj) (obj).rbegin(), (obj).rend()
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
using mint = atcoder::modint998244353;
using VL = vector<ll>;
using VVL = vector<VL>;
using VVVL = vector<VVL>;
using VM = vector<mint>;
using VVM = vector<VM>;
using VVVM = vector<VVM>;
using VD = vector<double>;
using VVD = vector<VD>;
using VVVD = vector<VVD>;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

template< typename T >
struct Combination {
  vector< T > _fact, _rfact, _inv;

  Combination(int sz) : _fact(sz + 1), _rfact(sz + 1), _inv(sz + 1) {
    _fact[0] = _rfact[sz] = _inv[0] = 1;
    for(int i = 1; i <= sz; i++) _fact[i] = _fact[i - 1] * i;
    _rfact[sz] /= _fact[sz];
    for(int i = sz - 1; i >= 0; i--) _rfact[i] = _rfact[i + 1] * (i + 1);
    for(int i = 1; i <= sz; i++) _inv[i] = _rfact[i] * _fact[i - 1];
  }

  inline T fact(int k) const { return _fact[k]; }

  inline T rfact(int k) const { return _rfact[k]; }

  inline T inv(int k) const { return _inv[k]; }

  T P(int n, int r) const {
    if(r < 0 || n < r) return 0;
    return fact(n) * rfact(n - r);
  }

  T C(int p, int q) const {
    if(q < 0 || p < q) return 0;
    return fact(p) * rfact(q) * rfact(p - q);
  }

  T H(int n, int r) const {
    if(n < 0 || r < 0) return (0);
    return r == 0 ? 1 : C(n + r - 1, r);
  }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll n, m; cin>>n>>m;
    VL cnt(n/2+1, 0);
    bool zero = n%2;
    rep(i,m){
        ll l, r; cin>>l>>r; l--;
        if((r-l)%2==0) cnt[(r-l)/2]++;
    }
    if(zero){
        cout<<0;
        return 0;
    }
    n /= 2;
    vector<P> arr;
    rep(i,n+1) if(cnt[i]) arr.push_back({i, cnt[i]});

    Combination<mint> c(2*n+1);
    VM cata(n+1, 0);
    rep(i,n+1) cata[i] = c.fact(2*i) * c.rfact(i+1) * c.rfact(i);

    VM dp(1, 1);
    for(auto [x, y]: arr){
        VM dp_(x*y+1, 0);
        rep(j, y+1) dp_[x*j] = cata[x].pow(j) * c.C(y, j) * (1-j%2*2);
        dp = atcoder::convolution(dp, dp_);
    }

    mint ans = 0;
    rep(i,dp.size()) ans += dp[i] * cata[n-i];
    cout<<ans.val();


    return 0;
}