#pragma GCC optimize("O3") #include using namespace std; using ll=long long; using P=pair; template using V=vector; #define fi first #define se second #define all(v) (v).begin(),(v).end() const ll inf=(1e18); //const ll mod=998244353; const ll mod=1000000007; ll GCD(ll a,ll b) {return b ? GCD(b,a%b):a;} ll LCM(ll c,ll d){return c/GCD(c,d)*d;} struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout< bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; } struct mint{ using ull=unsigned long long int; ull v; mint(ll vv=0){s(vv%mod+mod);} mint& s(ull vv){ v=vv>=1; } return res; } mint inv()const{return pow(mod-2);} //拡張ユークリッドの互除法 /* mint inv()const{ int x,y; int g=extgcd(v,mod,x,y); assert(g==1); if(x<0)x+=mod; return mint(x); }*/ friend ostream& operator<<(ostream&os,const mint&val){ return os<(const mint&val)const{return v>val.v;} }; bool root[1000005]; int cnt[1000005]; mint val[1000005]; mint ans=0; V g[1000005]; void dfs(int cur,int par){ if(cnt[cur]){ ans+=val[cur]; return; } for(int v:g[cur]){ if(v==par)continue; dfs(v,cur); cnt[cur]+=cnt[v]; val[cur]+=val[v]; } val[cur]+=mint(cnt[cur]); ans+=val[cur]; cnt[cur]++; return; } int main(){ int n; cin>>n; int a,b; for(int i=0;i>a>>b; g[a-1].push_back(b-1); root[b-1]=true; } for(int i=0;i