#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <string>
#include <cstring>
#include <chrono>
#include <random>
#include <bitset>
#include <array>
#include <climits>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <string>
#include <cstring>
#include <chrono>
#include <random>
#include <bitset>
#include <array>
#include <climits>

// #pragma GCC optimize("O3")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target("avx,avx2,fma")

using namespace std;

#define ll long long
#define ld long double

typedef complex<ld> point;

#define polar(r, t) ((r)*exp(point(0, (t))))
#define length(a) (hypot((a).imag(), (a).real()))
#define rotate(v, t) (polar(v, t))
#define X real()
#define Y imag()
#define cp(a, b) ((conj(a) * (b)).imag())
#define EPS 1e-13
// #define M_PI acosl(-1.0l)

const int N = 100 + 5, lg = 19, mod = 998244353;
const int M = 1e7 + 5;
const int INF = 1e9;

int k, n;

int main() {
    
    // loc[0]['I'] = 1;
    // loc[0]['J'] = 5;
    // loc[0]['L'] = 8;
    
    // loc[1]['L'] = 1;
    // loc[1]['O'] = 4;
    // loc[1]['S'] = 6;
    // loc[1]['T'] = 8;
    
    // loc[2]['L'] = 1;
    // loc[2]['O'] = 4;
    // loc[2]['T'] = 6;
    // loc[2]['Z'] = 8;
    
    cin >> n >> k;
    cin.ignore();
    map<string, int> count;
    while (k--) {
        string s;
        getline(cin , s);
        stringstream ss(s);
        int cnt = 0;
        while (ss >> s) {
            cnt++;
        }
        count[s] = max(count[s], cnt);
    }
    int ans = 0;
    for (auto &i : count) {
        ans += i.second;
    }
    if (ans <= n) {
        cout << "YES";
    } else {
        cout << "NO";
    }
    cout << '\n';
    return 0;
}