using System; using System.Linq; using System.Collections.Generic; public static class Program{ static int mod = 1000000007; public static void Main() { int[]np=Console.ReadLine().Split().Select(int.Parse).ToArray(); int n=np[0]; int p=np[1]; int[]a=new int[n+1]; a[0]=0; a[1]=1; for(int i=2;i<n;i++){ a[i]=Add(Mul(a[i-1],p),a[i-2]); } int sum=0; int sqsum=0; for(int i=0;i<n;i++){ AddAssign(ref sum,a[i]); AddAssign(ref sqsum,Mul(a[i],a[i])); } int ans=Mul(Add(Mul(sum,sum),sqsum),Inv(2)); Console.WriteLine(ans); } static void AddAssign(ref int x, int y){ x+=y; if(mod<=x)x-=mod; } static int Add(int x, int y){ AddAssign(ref x, y); return x; } static int Mul(int x, int y){ return (int)((long)x*y%mod); } static void MulAssign(ref int x, int y){ x=Mul(x,y); } static int Pow(int x, long y){ int ans=1; for(;y>0;y/=2){ if(y%2==1)MulAssign(ref ans,x); MulAssign(ref x,x); } return ans; } static int Inv(int x){ return Pow(x,mod-2); } }