#include<bits/stdc++.h>
#include<atcoder/modint>
#include<atcoder/convolution>
using namespace std;
using mint=atcoder::modint998244353;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N,M;
    cin>>N>>M;
    if(N&1){cout<<0<<endl;return 0;}
    N/=2;
    vector<mint>C(N+1);
    C[0]=1;
    for(int i=0;i<N;i++)C[i+1]=2*(2*i+1)*C[i]/(i+2);
    vector<vector<mint>>F;
    for(;M--;)
    {
        int l,r;
        cin>>l>>r;
        int a=r-l+1;
        if(a&1)continue;
        a/=2;
        vector<mint>f(a+1);
        f[0]=1;
        f[a]=-C[a];
        F.push_back(f);
    }
    auto dfs=[&](auto& dfs, int l, int r)->vector<mint>
    {
        if(F.empty())return {1};
        if(l+1==r)return F[l];
        int m=(r+l)/2;
        return atcoder::convolution(dfs(dfs,l,m),dfs(dfs,m,r));
    };
    auto f=dfs(dfs,0,F.size());
    mint ans=0;
    for(int i=0;i<f.size();i++)ans+=f[i]*C[N-i];
    cout << ans.val() << endl;
}