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

int main(){
  int N;
  int A[100000];
  cin >> N;
  
  int s=100001,l=0;
  for(int i=0;i<N;i++){
    cin >> A[i];
    if(A[i]>l) l=A[i];
    if(A[i]<s) s=A[i];
  }
  if(l-s==0){
    if(l+1==N || l*2<=N)
      cout << "Yes" << endl;
    else cout << "No";
    return 0;
  }else if(l-s==1){
    int C=l;
    int uni=0;
    for(int i=0;i<N;i++){
      if(A[i]==s) uni++;
    }
    if(C>uni && (C-uni)*2<=N-uni)
      cout << "Yes" << endl;
    else cout << "No" << endl;
    return 0;
  }else{
    cout << "No" << endl;
  }
  
  return 0;
}