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

int main() {
    ll N;
    int K;
    cin >> N >> K;
    ll A[K];
    set<ll> s;
    for (int i = 0; i < K; i++) {
        cin >> A[i];
        s.insert(A[i]);
    }
    if (K == 1) {
        cout << "Yes\n";
        return 0;
    }
    for (int i = 0; i < K; i++) {
        if (A[i] >= 9) {
            if (s.count(A[i] + 5)) {
                cout << "No\n";
                return 0;
            }
            if (s.count(A[i] + 3)) {
                cout << "No\n";
                return 0;
            }
            if (s.count(A[i] + 1)) {
                cout << "No\n";
                return 0;
            } 
        }
    }
    for (int i = 20; i >= 2; i--) {
        if (s.count(i) == 0) continue;
        if (s.count(i + 5)) s.insert(i - 1);
        if (s.count(i + 3)) s.insert(i - 2);
        if (s.count(i + 1)) s.insert(i - 3);
    }
    if (s.count(1)) {
        cout << "No\n";
    } else {
        cout << "Yes\n";
    }
    return 0;
}