using System; using System.Collections.Generic; using System.Collections; using System.Collections.Specialized; using System.Linq; using System.Text; using System.IO; using System.Reflection; using static System.Math; using System.Numerics; static class Program{ const int mod=(int)1e9+7; static List>[] li; static bool[] b; static void Main(){ Sc sc=new Sc(); var s=sc.Ia; int n=s[0],m=n-1; li=new List>[n+1]; b=new bool[n+1]; for(int i=1;i<=n;i++){ li[i]=new List>(); } for(int i=0;i>[] li; private readonly int[] at,ix,l; private readonly long[] de; private readonly int[][] g; private int f=0; public Alca(List>[] li,bool bo){ int n=li.Length,z=(n<<1)-1,m=z; this.li=li; at=new int[z]; ix=new int[n]; de=new long[n]; if(bo){Fu1(1,1);} else{ for(int i = 1;i>1]+1; } for(int i=1,k=1;ib){a^=b;b^=a;a^=b;} int p=l[b-a]; return at[de[at[g[p][a]]](int n,Func f){var a=new T[n];for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i