#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
typedef pair<db,db> pd;

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MX  = 2e5+5; 
const int MOD = 998244353;
const ll  INF = 1e18; 
const ld  PI  = acos((ld)-1);

const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1};
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
	return b < a ? a = b, 1 : 0; 
}
template<class T> bool ckmax(T& a, const T& b) { 
	return a < b ? a = b, 1 : 0; 
} 

constexpr int pct(int x) { return __builtin_popcount(x); } // number of ones 
constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
template<class T> T cdiv(T a, T b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 

int fstTrue(function<bool(int)> f, int lo, int hi) {
	hi++; assert(lo <= hi); // assuming f is increasing
	while (lo < hi) { // find first index such that f is true 
		int mid = (lo+hi)/2; 
		f(mid) ? hi = mid : lo = mid+1; 
	} 
	return lo;
}

template<class T> void remDup(vector<T>& v) { 
	sort(all(v)); v.erase(unique(all(v)),end(v)); 
}

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
	cerr << h; if (sizeof...(t)) cerr << ", ";
	DBG(t...); 
}
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)

// FILE I/O
void setIn(str S) { freopen(S.c_str(),"r",stdin); }
void setOut(str S) { freopen(S.c_str(),"w",stdout); }
void setIO(str S = "") {
	ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
	// cin.exceptions(cin.failbit); 
	// throws exception when do smth illegal
	// ex. try to read letter into int
	if (sz(S)) { setIn(S+".in"), setOut(S+".out"); } // for USACO
}

#pragma once

struct mi {
	typedef decay<decltype(MOD)>::type T; 
 	/// don't silently convert to T
	T v; explicit operator T() const { return v; }
	mi() { v = 0; }
	mi(ll _v) { 
		v = (-MOD < _v && _v < MOD) ? _v : _v % MOD;
		if (v < 0) v += MOD;
	}
	friend bool operator==(const mi& a, const mi& b) { 
		return a.v == b.v; 
	}
	friend bool operator!=(const mi& a, const mi& b) { 
		return !(a == b); 
	}
	friend bool operator<(const mi& a, const mi& b) { 
		return a.v < b.v; 
	}
	
	mi& operator+=(const mi& m) { 
		if ((v += m.v) >= MOD) v -= MOD; 
		return *this; 
	}
	mi& operator-=(const mi& m) { 
		if ((v -= m.v) < 0) v += MOD; 
		return *this; 
	}
	mi& operator*=(const mi& m) { 
		v = (ll)v*m.v%MOD; return *this; 
	}
	mi& operator/=(const mi& m) { return (*this) *= inv(m); }
	friend mi pow(mi a, ll p) {
		mi ans = 1; assert(p >= 0);
		for (; p; p /= 2, a *= a) if (p&1) ans *= a;
		return ans;
	}
	friend mi inv(const mi& a) { assert(a.v != 0); return pow(a,MOD-2); }
		
	mi operator-() const { return mi(-v); }
	mi& operator++() { return *this += 1; }
	mi& operator--() { return *this -= 1; }
	friend mi operator+(mi a, const mi& b) { return a += b; }
	friend mi operator-(mi a, const mi& b) { return a -= b; }
	friend mi operator*(mi a, const mi& b) { return a *= b; }
	friend mi operator/(mi a, const mi& b) { return a /= b; }
};
typedef vector<mi> vmi;
typedef pair<mi,mi> pmi;
typedef vector<pmi> vpmi;

vector<vmi> scmb; // small combinations
void genComb(int SZ) {
	scmb.assign(SZ,vmi(SZ)); scmb[0][0] = 1;
	FOR(i,1,SZ) F0R(j,i+1) 
		scmb[i][j] = scmb[i-1][j]+(j?scmb[i-1][j-1]:0);
}

template <class T, int ...Ns> struct BIT {
	T val = 0; void upd(T v) { val += v; }
	T query() { return val; }
};
template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
	BIT<T,Ns...> bit[N+1];
	template<typename... Args> void upd(int pos, Args... args) { assert(pos > 0);
		for (; pos<=N; pos+=pos&-pos) bit[pos].upd(args...); 
    }
	template<typename... Args> T sum(int r, Args... args) {
		T res=0; for (; r; r-=r&-r) res += bit[r].query(args...); 
		return res; 
    }
	template<typename... Args> T query(int l, int r, Args... args) { 
        return sum(r,args...)-sum(l-1,args...); 
    }
}; 
template<class T, int SZ> struct BITrange {
    BIT<T,SZ> bit[2];
    void upd(int lo, int hi, T val) {
        bit[0].upd(lo,val); bit[0].upd(hi+1,-val);
        bit[1].upd(lo,val*(lo-1)); bit[1].upd(hi+1,-val*hi);
    }
    T sum(int x) { return bit[0].sum(x)*x-bit[1].sum(x); }
    T query(int l, int r) { return sum(r)-sum(l-1); }
};

BITrange<mi,MX> bit;
int L[11],R[11];

int32_t main() { 
	
	setIO();

    int N,K; cin >> N >> K;

    F0R(i,K) cin >> L[i] >> R[i];

    bit.upd(1,1,1);
    FOR(i,1,N+1) {
        mi dp = bit.query(i,i);
        F0R(j,K) {
            int l = L[j], r = min(N-i,R[j]);
            if (l+i > N) continue;
            bit.upd(i+l,i+r,dp);
        }
    }

    cout << bit.query(N,N).v << "\n";

}	

Measured memory_bytes: 5228