#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

typedef long long ll;
const ll MAXN=105;
const ll MOD=1e9+7;

ll n,m;
ll a[MAXN];
ll d[MAXN][MAXN*2][MAXN*2];

int main(){
    scanf("%lld",&n); m=2*n-1;
    for(ll i=1;i<=m;i++) scanf("%lld",&a[i]);
    sort(a+1,a+m+1);
    d[n][0][0]=1;
    for(ll i=n;i>1;i--){
        ll l=(a[i]!=a[i-1]),r=(a[m-i+1]!=a[m-i+2]);
        for(ll j=0;j<=m;j++)
            for(ll k=0;k<=m;k++){
                if(!d[i][j][k]) continue;
                d[i-1][j+l][k+r]=(d[i-1][j+l][k+r]+d[i][j][k])%MOD;
                for(ll dl=0;dl<j+l;dl++) (d[i-1][dl][k+r+1]+=d[i][j][k])%=MOD;
                for(ll dr=0;dr<k+r;dr++) (d[i-1][j+l+1][dr]+=d[i][j][k])%=MOD;
            }
    }
    ll ans=0;
    for(ll i=0;i<=m;i++)
        for(ll j=0;j<=m;j++)
            ans=(ans+d[1][i][j])%MOD;
    printf("%lld\n",ans);
}
