using ll = long long;
ll mod = 1e9+7;
vector<vector<ll>> m;
ll N;
ll gcdExtended(ll a, ll b, ll *x, ll *y)
{
    if (a == 0)
    {
        *x = 0, *y = 1;
        return b;
    }

    ll x1, y1;
    ll gcd = gcdExtended(b%a, a, &x1, &y1);


    *x = y1 - (b/a) * x1;
    *y = x1;

    return gcd;
}
ll rev(ll b)
{
    ll m = mod;
    ll x, y; // used in extended GCD algorithm
    ll g = gcdExtended(b, m, &x, &y);

    // Return -1 if b and m are not co-prime
    if (g != 1)
        return -1;

    // m is added to handle negative x
    return (x%m + m) % m;
}
void print()
{
    for(int i=0; i<N; ++i)
    {
        string s;
         for(int j=0; j<N; ++j)
         {
             s+=to_string(m[i][j]);
             s+=' ';
         }
        cout<<s<<endl;
    }
    cout<<endl;
}
ll det_gaus()
{
    ll det=1;
    for(int i=0; i<N; ++i)
    {
        if( m[i][i] == 0)
        {
           for(int k = i + 1; k<N; ++k)
           {
                if(m[k][i] != 0)
                {
                    swap(m[k], m[i]);
                    break;
                }
           }
        }
        for(int k=i+1; k<N; ++k)
        {
            if(m[k][i] == 0)
            {
                continue;
            }
            ll m1 = m[k][i];
            ll m2 = m[i][i];
            m1%=mod;
            m2%=mod;
            det *= rev(m2);
            det %= mod;
            for(int j=i; j<N; ++j)
            {
                m[k][j] = m[k][j]*m2 - m[i][j]*m1;
                m[k][j]%=mod;
            }

        }
        det*=m[i][i];
        det%=mod;
    }
    print();
    return det;
}
int hierarchiesCount(int n, std::vector<std::vector<int>> respectList) {
    m.resize(n);
    for(auto&& v : m)
        v.resize(n);
    vector<int> d(n);
    for(auto& e : respectList)
    {
        ++d[e[0]];
        ++d[e[1]];
        m[e[0]][e[1]] = -1;
        m[e[1]][e[0]] = -1;

    }
    for(int i=0; i<n; ++i)
    {
        m[i][i] = d[i];
    }
    N=n-1;
    print();
    ll ans = abs(det_gaus())%mod;
    ans*=n%mod;
    ans%=mod;
    return ans;
}