#include<cstdio>
#define N 5
#define ll long long
using namespace std;
int n;ll a[N];const ll mod=1e9+7;
void exgcd(ll a,ll b,ll &x,ll &y)
{
	if(!b){x=1;y=0;return;}
	exgcd(b,a%b,y,x);
	y-=a/b*x;
}
ll C(ll m,ll n)
{
	if(!m)return 1;
	ll sum=1,num=1,x,y;
	for(int i=1;i<=m;i++,n--)sum=sum*n%mod,num=num*i%mod;
	exgcd(num,mod,x,y);
	return (sum*x%mod+mod)%mod;
}
int main(){
	freopen("moorouteg.in","r",stdin);freopen("moorouteg.out","w",stdout);
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d",a+i);
	for(int i=1;i<=n;i++)if(a[i]&1)return !printf("0");else a[i]>>=1;
	if(n==1)return !printf("1");
	if(a[1]<a[2])
		printf("%lld",C(a[2]-a[1],a[2]-1));
	else
		printf("%lld",C(a[2]-a[1],a[2]));
	return 0;
}