#include<iostream>
#include<algorithm>
using namespace std;
#define fr(i,n) for(int i=0;i<n;i++)

int main(){
  int n,a[100010],b,c;
  cin>>n;
  fr(i,n) cin>>a[i];
  sort(a,a+n);
  if(a[n-1]-a[0]>1){
    cout<<"No"<<endl;
    return 0;
  }
  b=a[0];
  if(a[0]==a[n-1]){
    if(b<=n/2 || b==n-1) cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
  }
  fr(i,n){
    if(a[i]>b){
      c=i;
      break;
    }
  }
  if(b-c+1<=0 || 2*(b-c+1)>n-c) cout<<"No"<<endl;
  else cout<<"Yes"<<endl;
}