#include<bits/stdc++.h>
using namespace std;
int a[200100],n,mn,flag,p;
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;++i)
		scanf("%d",&a[i]);
	mn=a[1];
	for(int i=1;i<=n;++i)mn=min(mn,a[i]);
	for(int i=1;i<=n;++i){
		if(a[i]!=mn)flag=true,p++;
		if(a[i]!=mn&&a[i]!=mn+1)return puts("No"),0;
	}
		
	if(flag){
		if(p==1)return puts("No"),0;
		int ans1=0;
		for(int i=1;i<=n;++i)if(a[i]==mn)ans1++;
		if(ans1+1>mn+1||ans1+(n-ans1)/2<mn+1)return puts("No"),0;
		else return puts("Yes"),0;
	} else {
		if(n/2<mn&&mn+1!=n)return puts("No"),0;
		else return puts("Yes"),0;
	}
}