#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	ll N, K;
	cin >> N >> K;
	vector<ll> A(K);
	REP(i, K) scanf("%lld", &A[i]);
	vector<ll> B = A;
	REP(i, K) FOR(j, 1, 15) if (A[i] - j > 0) B.emplace_back(A[i] - j);
	B.emplace_back(1);
	sort(ALL(B));
	B.erase(unique(ALL(B)), B.end());
	REP(i, K) A[i] = lower_bound(ALL(B), A[i]) - B.begin();
	
	puts([&]() -> bool {
		vector<bool> ok(B.size(), true);
		REP(i, K) ok[A[i]] = false;
		for (int i = B.size() - 1; i >= 0; --i) {
			FOR(j, 1, 4) {
				const int t1 = lower_bound(ALL(B), B[i] + j) - B.begin();
				const int t2 = lower_bound(ALL(B), B[i] + 7 - j) - B.begin();
				if (t1 == B.size() || t2 == B.size()) continue;
				if (B[t1] != B[i] + j || B[t2] != B[i] + 7 - j) continue;
				if (ok[t1] || ok[t2]) continue;
				ok[i] = false;
				break;
			}
			if (i + 6 <= B.size()) {
				bool ng = true;
				REP(j, 6) ng &= B[i + j] == B[i] + j && !ok[i + j];
				if (ng) return false;
			}
		}
		return ok[lower_bound(ALL(B), 1) - B.begin()];
	}() ? "Yes": "No");
}