#include <algorithm>
#include <bitset>
#include <tuple>
#include <cstdint>
#include <cctype>
#include <assert.h>
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <limits>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include <math.h>
#include <cstring>
#include <array>
using namespace std;
using lint = long long;
const int dx[] = { 1,0,-1,0 };
const int dy[] = { 0,1,0,-1 };

const lint INF = 1ll << 60;
const int mod = 1000000007;
void speed() {
	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);
	return;
}


int main(void) {
	speed();
	lint n; cin >> n;
	int k; cin >> k;
	map<lint, bool> r;
	for (int i = 0; i < k; i++) {
		lint s; cin >> s;
		r[s] = true;
	}
	for (auto s : r) {
		for (int i = 1; i <= min(6ll, n - s.first); i++) {
			if (r[s.first + i]) {
				puts("No");
				return 0;
			}
		}
	}
	puts("Yes");
	
	return 0;
}