#include <bits/stdc++.h>

#define rep(X, N) for (ll X = 0LL; X < (N); X++)
#define ALL(V) (V).begin(), (V).end()
#define endl "\n"

using namespace std;
typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;

const double PI = 3.1415926535897932384626;
const ll MODN = 1000000007;
const ll MODN2 = 998244353;

int ceil_pow2(int n) {
    int x = 0;
    while ((1U << x) < (unsigned int)(n)) x++;
    return x;
}

template <class S,
          S (*op)(S, S),
          S (*e)(),
          class F,
          S (*mapping)(F, S),
          F (*composition)(F, F),
          F (*id)()>
struct lazy_segtree {
  public:
    lazy_segtree() : lazy_segtree(0) {}
    lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {}
    lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) {
        log = ceil_pow2(_n);
        size = 1 << log;
        d = std::vector<S>(2 * size, e());
        lz = std::vector<F>(size, id());
        for (int i = 0; i < _n; i++) d[size + i] = v[i];
        for (int i = size - 1; i >= 1; i--) {
            update(i);
        }
    }

    void set(int p, S x) {
        assert(0 <= p && p < _n);
        p += size;
        for (int i = log; i >= 1; i--) push(p >> i);
        d[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) {
        assert(0 <= p && p < _n);
        p += size;
        for (int i = log; i >= 1; i--) push(p >> i);
        return d[p];
    }

    S prod(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        if (l == r) return e();

        l += size;
        r += size;

        for (int i = log; i >= 1; i--) {
            if (((l >> i) << i) != l) push(l >> i);
            if (((r >> i) << i) != r) push(r >> i);
        }

        S sml = e(), smr = e();
        while (l < r) {
            if (l & 1) sml = op(sml, d[l++]);
            if (r & 1) smr = op(d[--r], smr);
            l >>= 1;
            r >>= 1;
        }

        return op(sml, smr);
    }

    S all_prod() { return d[1]; }

    void apply(int p, F f) {
        assert(0 <= p && p < _n);
        p += size;
        for (int i = log; i >= 1; i--) push(p >> i);
        d[p] = mapping(f, d[p]);
        for (int i = 1; i <= log; i++) update(p >> i);
    }
    void apply(int l, int r, F f) {
        assert(0 <= l && l <= r && r <= _n);
        if (l == r) return;

        l += size;
        r += size;

        for (int i = log; i >= 1; i--) {
            if (((l >> i) << i) != l) push(l >> i);
            if (((r >> i) << i) != r) push((r - 1) >> i);
        }

        {
            int l2 = l, r2 = r;
            while (l < r) {
                if (l & 1) all_apply(l++, f);
                if (r & 1) all_apply(--r, f);
                l >>= 1;
                r >>= 1;
            }
            l = l2;
            r = r2;
        }

        for (int i = 1; i <= log; i++) {
            if (((l >> i) << i) != l) update(l >> i);
            if (((r >> i) << i) != r) update((r - 1) >> i);
        }
    }

    template <bool (*g)(S)> int max_right(int l) {
        return max_right(l, [](S x) { return g(x); });
    }
    template <class G> int max_right(int l, G g) {
        assert(0 <= l && l <= _n);
        assert(g(e()));
        if (l == _n) return _n;
        l += size;
        for (int i = log; i >= 1; i--) push(l >> i);
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!g(op(sm, d[l]))) {
                while (l < size) {
                    push(l);
                    l = (2 * l);
                    if (g(op(sm, d[l]))) {
                        sm = op(sm, d[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, d[l]);
            l++;
        } while ((l & -l) != l);
        return _n;
    }

    template <bool (*g)(S)> int min_left(int r) {
        return min_left(r, [](S x) { return g(x); });
    }
    template <class G> int min_left(int r, G g) {
        assert(0 <= r && r <= _n);
        assert(g(e()));
        if (r == 0) return 0;
        r += size;
        for (int i = log; i >= 1; i--) push((r - 1) >> i);
        S sm = e();
        do {
            r--;
            while (r > 1 && (r % 2)) r >>= 1;
            if (!g(op(d[r], sm))) {
                while (r < size) {
                    push(r);
                    r = (2 * r + 1);
                    if (g(op(d[r], sm))) {
                        sm = op(d[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(d[r], sm);
        } while ((r & -r) != r);
        return 0;
    }

  private:
    int _n, size, log;
    std::vector<S> d;
    std::vector<F> lz;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
    void all_apply(int k, F f) {
        d[k] = mapping(f, d[k]);
        if (k < size) lz[k] = composition(f, lz[k]);
    }
    void push(int k) {
        all_apply(2 * k, lz[k]);
        all_apply(2 * k + 1, lz[k]);
        lz[k] = id();
    }
};

long long gcd(long long a, long long b){
    if (a < b)
        swap(a, b);
    assert(b != 0);
    if (a % b == 0)
        return b;
    return gcd(b, a % b);
}

class ModInt
{
    int _mod;
    long long x;

public:
    ModInt() {}
    ModInt(long long _x, int m)
    {
        _mod = m;
        x = _x % m;
        if (x < 0)
            x += m;
    }

    int val()
    {
        return (int)x;
    }

    int mod()
    {
        return _mod;
    }

    ModInt &operator++()
    {
        x++;
        if (x == _mod)
            x = 0;
        return *this;
    }

    ModInt &operator--()
    {
        if (x == 0)
            x = _mod;
        x--;
        return *this;
    }

    ModInt &operator+=(const ModInt &rhs)
    {
        x += rhs.x;
        if (x >= _mod)
            x -= _mod;
        return *this;
    }

    ModInt &operator-=(const ModInt &rhs)
    {
        x -= rhs.x;
        if (x < 0)
            x += _mod;
        return *this;
    }

    ModInt &operator*=(const ModInt &rhs)
    {
        x *= rhs.x;
        if (x >= _mod)
            x = x % _mod;
        return *this;
    }

    ModInt operator+() const
    {
        return *this;
    }

    ModInt operator-() const
    {
        return ModInt(-x, _mod);
    }

    friend ModInt operator+(const ModInt &lhs, const ModInt &rhs)
    {
        return ModInt(lhs) += rhs;
    }

    friend ModInt operator-(const ModInt &lhs, const ModInt &rhs)
    {
        return ModInt(lhs) -= rhs;
    }

    friend ModInt operator*(const ModInt &lhs, const ModInt &rhs)
    {
        return ModInt(lhs) *= rhs;
    }

    ModInt pow(long long n) const
    {
        if (n == 0)
        {
            return ModInt(1, _mod);
        }
        else if (n % 2 == 1)
        {
            ModInt tmp = pow((n - 1) / 2);
            return tmp * tmp * ModInt(x, _mod);
        }
        else
        {
            ModInt tmp = pow(n / 2);
            return tmp * tmp;
        }
    }

    ModInt inv() const
    {
        assert(gcd(x, _mod) == 1);
        assert(_mod >= 2);
        return pow(_mod - 2);
    }

    ModInt &operator/=(const ModInt &rhs)
    {
        return (*this) = (*this) * rhs.inv();
    }

    friend ModInt operator/(const ModInt &lhs, const ModInt &rhs)
    {
        return ModInt(lhs) /= rhs;
    }

    friend bool operator==(const ModInt &lhs, const ModInt &rhs)
    {
        return lhs.x == rhs.x;
    }

    friend bool operator!=(const ModInt &lhs, const ModInt &rhs)
    {
        return lhs.x != rhs.x;
    }
};

class ModIntGen
{
    int modn;

public:
    ModIntGen() {}
    ModIntGen(int n)
    {
        assert(0 < n && n < INT_MAX);
        modn = n;
    }

    ModInt g(long long x)
    {
        return ModInt(x, modn);
    }
};

ModInt op(ModInt m0, ModInt m1){
    return m0 + m1;
}

ModInt e(){
    return ModInt(0, MODN2);
}

class Func{
public:
    ModInt m;

    Func(ModInt mo){
        m = mo;
    }
};

ModInt mapping(Func f, ModInt m){
    return f.m + m;
}

Func composition(Func f, Func g){
    return Func(f.m + g.m);
}

Func id(){
    return Func(ModInt(0, MODN2));
}

int main(){

    int n, k;
    cin >> n>> k;

    vector<pair<int, int>> range(k);

    rep(i, k){
        cin >> range[i].first >> range[i].second;
    }

    ModIntGen mg(MODN2);

    lazy_segtree<ModInt, op, e, Func, mapping, composition, id> lst(n * 2 + 1);

    lst.set(1, mg.g(1));

    for(int i = 1; i <= n - 1; i++){
        rep(j, k){
            lst.apply(i + range[j].first, i + range[j].second + 1, Func(lst.get(i)));
        }
    }

    cout << lst.get(n).val() << endl;

    return 0;
}


Measured memory_bytes: 33988