#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
inline int my_getchar_unlocked(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread_unlocked(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline void rd(long long &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite_unlocked(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar_unlocked(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar_unlocked(a);
}
inline void wt_L(const char c[]){
  int i=0;
  for(i=0;c[i]!='\0';i++){
    my_putchar_unlocked(c[i]);
  }
}
int N;
int K;
set<long long> A;
int main(){
  int Lj4PdHRW;
  int fg;
  int sq;
  long long b;
  rd(N);
  rd(K);
  for(Lj4PdHRW=(0);Lj4PdHRW<(K);Lj4PdHRW++){
    rd(b);
    A.insert(b);
  }
  while(A.size()){
    long long t = *A.rbegin();
    fg = A.size();
    for(long long i : A){
      if(i == t-1 && i-3 > 0){
        A.insert(i-3);
      }
      if(i == t-3 && i-2 > 0){
        A.insert(i-2);
      }
      if(i == t-5 && i-1 > 0){
        A.insert(i-1);
      }
    }
    if(fg == A.size()){
      A.erase(t);
    }
    if(A.count(1)){
      wt_L("No");
      wt_L('\n');
      return 0;
    }
    b = -1;
    for(long long i : A){
      if(i == b+1){
        sq++;
      }
      else{
        sq = 1;
      }
      if(sq >= 6){
        wt_L("No");
        wt_L('\n');
        return 0;
      }
      b = i;
    }
  }
  wt_L("Yes");
  wt_L('\n');
  return 0;
}
// cLay varsion 20200926-1

// --- original code ---
// int N, K; set<ll> A;
// {
//   int fg, sq; ll b;
//   rd(N,K);
//   rep(K) rd(b), A.insert(b);
//   while(A.size()){
//     ll t = *A.rbegin();
//     fg = A.size();
//     for(ll i : A){
//       if(i == t-1 && i-3 > 0) A.insert(i-3);
//       if(i == t-3 && i-2 > 0) A.insert(i-2);
//       if(i == t-5 && i-1 > 0) A.insert(i-1);
//     }
//     if(fg == A.size()) A.erase(t);
//     if(A.count(1)) wt("No"), return 0;
// 
//     b = -1;
//     for(ll i : A){
//       if(i == b+1) sq++; else sq = 1;
//       if(sq >= 6) wt("No"), return 0;
//       b = i;
//     }
// 
// //    for(ll i : A) wtSp(i); wt("");
//   }
//   wt("Yes");
// }