#include "bits/stdc++.h"
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
typedef long long ll;
#define vi vector<ll>
#define all(a) a.begin(),a.end()
typedef pair<int,int> P;
const long long mod=1000000007;
ll kj[200006],kji[200006];
ll modpow(ll a,ll x){
  ll res=1;
  while(x){
    if(x&1)res=res*a%mod;
    a=a*a%mod;
    x>>=1;
  }
  return res;
}
void setkj(){
  ll maxA=200000;
  kj[0]=1;
  rep(i,maxA)kj[i+1]=kj[i]*(i+1)%mod;
  rep(i,maxA+1)kji[i]=modpow(kj[i],mod-2);
}
ll comb(ll r,ll c){
  return kj[r]*kji[c]%mod*kji[r-c]%mod;
}

signed main(){
  setkj();
  ll n,k;cin>>n>>k;
  k%=mod;
  ll m=k*(k+1)/2%mod;
  ll ans=0;
  rep(i,n){
    ans+=comb(n,i)*modpow(m,i)%mod*modpow(k,n-i);
    ans%=mod;
  }
  cout<<ans<<endl;
}