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// #pragma GCC optimize(2)
// #pragma GCC optimize(3)
// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
// #pragma GCC target("avx,avx2,fma")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double lld;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll, ll> ppl;
#define ain(a,n) for(ll i=0;i<(n);++i)  cin>>(a)[i];
#define DEBUG(x) cout << '>' << #x << ':' << x << endl;
#define loop(i,n) for(ll i=0;i<(n);++i)
#define FOR(i,a,b) for(ll i=(a);i<=(b);++i)
#define FORD(i,a,b) for(ll i=(a);i>=(b);--i)
#define cases ll T=0;cin>>T;while(T--)
#define ff first
#define ss second
#define all(v) v.begin(),v.end()
#define END "\n"
#define pb push_back
#define mp make_pair
#define go(c,itr) for(auto itr=(c).begin(); itr!=(c).end(); ++itr)
// #define back(c,itr) for(auto itr=(c).rbegin(); itr!=(c).rend(); ++itr)
#define PI 3.14159265359
#define inf 9e18
#define MOD 1000000007
#define MODU 998244353
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define MAXN 1000005
#define BLOCK 555
const string alpha = "abcdefghijklmnopqrstuvwxyz";
const ll N = 200005;
const long double epsilon = 1e-9;
inline ll myceil(ll a, ll b) { if (a % b == 0)  return (a / b); return (a / b + 1);}
ll spf[MAXN];
void sieve()
{
    spf[1] = 1;
    for (ll i = 2; i < MAXN; i++)
        spf[i] = i;

    for (ll i = 4; i < MAXN; i += 2)
        spf[i] = 2;

    for (ll i = 3; i * i < MAXN; i++)
    {
        if (spf[i] == i)
        {
            for (ll j = i * i; j < MAXN; j += i)
                if (spf[j] == j)
                    spf[j] = i;
        }
    }
}
inline ll binlen(ll n) {
    ll c = 0;
    while (n > 0)
        ++c , n /= 2;
    return c;
}
ll binexp(ll a, ll b, ll m) {
    a %= m;
    ll res = 1;
    while (b > 0) {
        if (b & 1)
            res = res * a % m;
        a = a * a % m;
        b >>= 1;
    }
    return res;
}
ll modinvfermat(ll a, ll m)
{
    return binexp(a, m - 2, m);
}
void task(bool flag)
{
    if (flag)
        cout << "YES\n";
    else
        cout << "NO\n";
}
ll lcm(ll a, ll b)
{
    return ((1LL * a * b) / (__gcd(a, b)));
}



signed main() {
// #ifndef ONLINE_JUDGE
//     freopen("input.txt", "r", stdin);
//     freopen("output.txt", "w", stdout);
// #endif
    fast
    ll n, k;
    cin >> n >> k;
    vl a;
    vector<ppl> lr(k);
    loop(i, k)
    {
        cin >> lr[i].ff >> lr[i].ss;
    }
    loop(i, k) {
        FOR(j, lr[i].ff, lr[i].ss)
        {
            a.pb(j);
        }
    }
    sort(all(a));
    ll m = a.size();
    vl dp(n + 1, 0);
    dp[1] = 1;
    FOR(i, 1, n)
    {
        loop(j, m)
        {
            if (i - a[j] < 0)
                continue;
            (dp[i] += dp[i - a[j]]) %= MODU;
        }
    }
    cout << dp[n] << END;



// #ifndef ONLINE_JUDGE
//     cout << "\nTime Elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " sec\n";
// #endif
    return 0;
}
