#include #define rep(i,n) for(int i=0;i<(int)(n);i++) #define FOR(i,n,m) for(int i=(int)(n); i<=(int)(m); i++) #define RFOR(i,n,m) for(int i=(int)(n); i>=(int)(m); i--) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define RITR(x,c) for(__typeof(c.rbegin()) x=c.rbegin();x!=c.rend();x++) #define setp(n) fixed << setprecision(n) template bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; } #define ll long long #define vll vector #define vi vector #define pll pair #define pi pair #define all(a) (a.begin()),(a.end()) #define rall(a) (a.rbegin()),(a.rend()) #define fi first #define se second #define pb push_back #define ins insert #define debug(a) cerr<<(a)< ostream &operator<<(ostream &os, const pair &p){return os<<"("< istream &operator>>(istream &is, pair &p){return is>>p.fi>>p.se;} /* Some Libraries */ //------------------------------------------------- int main(void) { cin.tie(0); ios::sync_with_stdio(false); ll N,K; cin>>N>>K; vll a(K); rep(i,K) cin>>a[i], a[i]--; sort(all(a)); rep(i,K)FOR(j,i+1,K-1){ ll diff = a[j]-a[i]; if (diff==1 || diff==3 || diff==5){ if (a[i]>=100){ cout<<"No\n"; return 0; } } } vector table(110,false); rep(i,K)if(a[i]<100){ table[a[i]]=true; } RFOR(i,99,0){ if (table[i]) continue; bool ng=false; if (table[i+1] && table[i+6]) ng=true; if (table[i+2] && table[i+5]) ng=true; if (table[i+3] && table[i+4]) ng=true; table[i] = ng; } cout<<(table[0]?"No":"Yes")<<"\n"; return 0; }