#include <cmath>
#include <cstring>
#include <cstdio>
#include <algorithm>

using namespace std;

int n,x,y,color,ans;
int a[100010];

int main(){
	scanf("%d",&n);
	color=0;
	for (int i=1;i<=n;++i){
		scanf("%d",&a[i]);
		color=max(color,a[i]);
	}
	for (int i=1;i<=n;++i){
		if (color-1>a[i]){
			puts("No");
			return 0;
		}
		if (color-1==a[i]) ++x;
	}
	y=n-x;
	if (x==0 && color==n-1){
		puts("Yes");
		return 0;
	}
	if (color==x){
		puts("No");
		return 0;
	}
	if (y/(color-x)>1) puts("Yes");
	else puts("No");
}