#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define srep(i, s, n) for (int i=(s); i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define fore(i,x) for(auto i:x)
#define pb push_back

using vi=vector<int>;
using vvi=vector<vi>;
using vb=vector<bool>;
using vvb=vector<vb>;
using vs=vector<string>;
using vll=vector<long long>;
using vvll=vector<vll>;
using vc=vector<char>;
using vvc=vector<vc>;
using ll=long long;

void Yes(bool ok){ cout << (ok ? "Yes" : "No") << "\n";}

int main(){
    ll N,K; cin >> N >> K;
    vll A(K);
    rep(i,K) cin >> A.at(i);
    vb GO(30);
    
    rep(i,K-1){
        ll d=A.at(i+1)-A.at(i);
        if(d==1 || d==3 || d==5){
            if(A.at(i)<=20){
                GO.at(A.at(i+1))=true;
                GO.at(A.at(i))=true;
                for(int j=24;j>=0;j--){
                    if(j-3>=0){
                        if(GO.at(j) && GO.at(j+1)) GO.at(j-3)=true;
                    }
                    if(j-2>=0){
                        if(GO.at(j) && GO.at(j+3)) GO.at(j-2)=true;
                    }
                    if(j-1>=0){
                        if(GO.at(j) && GO.at(j+5)) GO.at(j-1)=true;
                    }
                }
            }
            else GO.at(1)=true;
        }
    }
    Yes(!GO.at(1)); 
    
}