#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vb = vector<bool>;
using P = pair<ll, ll>;
template <typename T> using pq = priority_queue<T>;
template <typename T> using minpq = priority_queue<T, vector<T>, greater<T>>;
template <typename T, typename K> using ump = unordered_map<T, K>;
const ll dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ll mod = 998244353;
const ll inf = ll(1e9);
const ll e5 = ll(1e5);
const ll ll_inf = ll(1e9) * ll(1e9);

#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define repr(i, n) for (ll i = ll(n - 1); i >= 0; i--)
#define each(i, mp) for (auto &i : mp)
#define eb emplace_back
#define F first
#define S second
#define all(obj) (obj).begin(), (obj).end()

template <class T> ostream &operator<<(ostream &out, const vector<T> &list) {
    ll n = list.size();
    rep(i, n) out << list[i] << ' ';
    return out;
}

template <class T> istream &operator>>(istream &in, vector<T> &list) {
    ll n = list.size();
    rep(i, n) in >> list[i];
    return in;
}

template <class T> ostream &operator<<(ostream &out, const vector<vector<T>> &list) {
    ll n = list.size();
    rep(i, n) out << list[i] << '\n';
    return out;
}

/* ------------- ANSWER ------------- */
/* ---------------------------------- */
// sample: http://beet-aizu.hatenablog.com/entry/2017/12/01/225955
// verified with
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_A
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_F
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_G
template <typename Data, typename Lazy> struct SegmentTree {
public:
    bool isLazy = false;
    int sz;
    vector<Data> seg;
    vector<Lazy> lazy;

    // mergeするときの操作
    using MergeData = function<Data(Data, Data)>;
    // lazyをxでupdate
    using UpdateLazyFromX = function<Lazy(Lazy, Lazy)>;
    // dataをlazyでupdate
    using UpdateDataFromLazy = function<Data(Data, Lazy)>;
    // lenが与えられた時にlazyを計算
    using CalcLazyWithLen = function<Lazy(Lazy, ll)>;

    // lazy
    // O(N)
    SegmentTree(int n, const MergeData fm, const UpdateLazyFromX fl, const UpdateDataFromLazy fa,
                const CalcLazyWithLen fw, Data M1, Lazy A1)
        : fm(fm), fl(fl), fa(fa), fw(fw), M1(M1), A1(A1) {
        isLazy = true;
        sz = 1;
        while (sz < n) sz *= 2;
        seg.assign(2 * sz - 1, M1);
        lazy.assign(2 * sz - 1, A1);
    }

    // not lazy
    SegmentTree(int n, const MergeData fm, Data M1)
        : fm(fm),
          M1(M1),
          // ここからdummy
          fl([M1](Data a, Data b) { return M1; }),
          fa([M1](Data a, Lazy b) { return M1; }),
          fw([M1](Lazy a, ll b) { return M1; }),
          A1(M1) {
        isLazy = false;
        sz = 1;
        while (sz < n) sz *= 2;
        seg.assign(2 * sz - 1, M1);
    }

    // not lazy
    // O(logN)
    Data update(int i, Data x) {
        i += sz - 1;
        seg[i] = x;
        while (i > 0) {
            i = (i - 1) / 2;
            seg[i] = fm(seg[2 * i + 1], seg[2 * i + 2]);
        }
    }

    void build(const vector<Data> &v) {
        ll n = v.size();
        rep(i, n) seg[i + sz - 1] = v[i];
        for (ll i = sz - 2; i >= 0; --i) {
            seg[i] = fm(seg[i * 2 + 1], seg[i * 2 + 2]);
        }
    }

    // for lazy only
    // O(logN)
    Data update(int a, int b, Data x) { return update(a, b, x, 0, 0, sz); }

    // O(logN)
    Data query(int a, int b) { return query(a, b, 0, 0, sz); }

private:
    const MergeData fm;
    const UpdateLazyFromX fl;
    const UpdateDataFromLazy fa;
    const CalcLazyWithLen fw;
    const Data M1;
    const Lazy A1;

    void eval(int len, int k) {
        if (lazy[k] == A1) return;
        if (k * 2 + 1 < sz * 2 - 1) {
            lazy[2 * k + 1] = fl(lazy[2 * k + 1], lazy[k]);
            lazy[2 * k + 2] = fl(lazy[2 * k + 2], lazy[k]);
        }
        seg[k] = fa(seg[k], fw(lazy[k], len));
        lazy[k] = A1;
    }

    Data update(int a, int b, Data x, int k, int l, int r) {
        eval(r - l, k);
        if (r <= a || b <= l) return seg[k];
        if (a <= l && r <= b) {
            lazy[k] = fl(lazy[k], x);
            return fa(seg[k], fw(lazy[k], r - l));
        }
        return seg[k] = fm(update(a, b, x, k * 2 + 1, l, (l + r) / 2), update(a, b, x, k * 2 + 2, (l + r) / 2, r));
    }

    Data query(int a, int b, int k, int l, int r) {
        if (isLazy) eval(r - l, k);
        if (r <= a || b <= l) return M1;
        if (a <= l && r <= b) return seg[k];
        Data vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
        Data vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
        return fm(vl, vr);
    }
};

SegmentTree<ll, ll> RangeMinimumTree(int n) {
    auto fm = [](ll a, ll b) { return min(a, b); };
    auto fl = [](ll a, ll b) { return b; };
    auto fa = [](ll a, ll b) { return b; };
    auto fw = [](ll a, ll w) { return a; };
    SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, LONG_MAX, LONG_MAX);
    return tree;
}

SegmentTree<ll, ll> RangeMaxTree(int n) {
    auto fm = [](ll a, ll b) { return max(a, b); };
    auto fl = [](ll a, ll b) { return b; };
    auto fa = [](ll a, ll b) { return b; };
    auto fw = [](ll a, ll w) { return a; };
    SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, LONG_MIN, LONG_MIN);
    return tree;
}

SegmentTree<ll, ll> RangeSumTree(int n) {
    auto fm = [](ll a, ll b) { return (a + b) % mod; };
    auto fl = [](ll a, ll b) { return (a + b) % mod; };
    auto fa = [](ll a, ll b) { return (a + b) % mod; };
    auto fw = [](ll a, ll w) { return (a * w) % mod; };
    SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, 0, 0);
    return tree;
}

void solve() {
    ll n, k;
    cin >> n >> k;
    SegmentTree<ll, ll> tree = RangeSumTree(n + 1);
    vl imos(n + 2);
    rep(i, k) {
        ll l, r;
        cin >> l >> r;
        imos[l]++, imos[r + 1]--;
    }
    ll cnt = 0;
    ll start = 0;
    vector<P> lrs;
    rep(i, n + 2) {
        if (cnt == 0 && imos[i] > 0) start = i;
        ll newCnt = cnt + imos[i];
        if (cnt > 0 && newCnt == 0) lrs.emplace_back(P{start, i - 1});
        cnt = newCnt;
    }

    tree.update(0, 1, 1);
    rep(i, n) {
        each(e, lrs) {
            ll l = i + e.first, r = i + e.second;
            if (l > n - 1) continue;
            r = min(n - 1, r);
            tree.update(l, r + 1, tree.query(i, i + 1));
        }
    }

    cout << tree.query(n - 1, n) << '\n';
}

int main() {
#ifdef MY_DEBUG
    while (true) {
#endif
        solve();
#ifdef MY_DEBUG
    }
#endif
    return 0;
}


Measured memory_bytes: 13080