#include<cstdio>
#define neko 100010
#define qwq return printf("Yes\n"),0
#define orz return printf("No\n"),0
#define f(i,a,b) for(register int i=(a);i<=(b);i=-(~i))
int n,minx=1e9,maxn,a[neko],cnt;
int cmin(int a,int b){return a<b?a:b;}
int cmax(int a,int b){return a>b?a:b;}
int main()
{
	scanf("%d",&n);
	f(i,1,n)scanf("%d",&a[i]),minx=cmin(minx,a[i]),maxn=cmax(maxn,a[i]);
	if(minx==maxn)
	{
		if(minx==n-1)qwq;
		else if(2*minx>n)orz;
		else qwq;
	}
	else if(minx<maxn-1)orz;
	else
	{
		f(i,1,n)if(minx==a[i])++cnt;
		if(maxn-cnt<=0)orz;
		else if(2*(maxn-cnt)>(n-cnt))orz;
		else qwq;
	}
}