#include <iostream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cassert>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <utility>
#define llint long long
#define inf 1e18
#define rep(x, s, t) for(llint (x) = (s); (x) < (t); (x)++)
#define Rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++)
#define chmin(x, y) (x) = min((x), (y))
#define chmax(x, y) (x) = max((x), (y))

using namespace std;
typedef pair<llint, llint> P;

llint n, k;
llint a[105];
bool dp[10000005];

bool calc(vector<llint> &vec)
{
	if(vec.size() == 0) return true;
	llint l = max(0LL, vec.front() - 1000);
	
	for(int i = 0; i < vec.size(); i++) vec[i] -= l;
	llint r = vec.back()+1;
	for(int i = 0; i <= r+10; i++) dp[r] = false;
	
	for(int i = 0; i < vec.size(); i++) dp[vec[i]] = true;
	for(int i = r; i >= 0; i--){
		if(dp[i+1]&&dp[i+6]) dp[i] = true;
		if(dp[i+2]&&dp[i+5]) dp[i] = true;
		if(dp[i+3]&&dp[i+4]) dp[i] = true;
	}
	//for(int i = 0; i <= r; i++) cout << dp[i]; cout << endl;
	return !dp[0];
}

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> k;
	for(int i = 1; i <= k; i++) cin >> a[i], a[i]--;
	
	vector<llint> vec;
	for(int i = 1; i <= k; i++){
		if(a[i] > a[i-1] + 1000){
			if(!calc(vec)){
				cout << "No" << endl;
				return 0;
			}
			vec.clear();
		}
		vec.push_back(a[i]);
	}
	if(!calc(vec)){
		cout << "No" << endl;
		return 0;
	}
	cout << "Yes" << endl;
	
	return 0;
}