#include <math.h>
#include <stdio.h>
#include <string.h>
#include <vector>
#include <string>
#include <queue>
#include <map>
#include <algorithm>
#include <cmath>
#include <iostream>
#include <sstream>
#include <set>
using namespace std;
const int mmod = 1000000007;
int inv_mod(int a, int b) {
if (a == 1) return b;
int div = mmod / a + 1;
return inv_mod((a * (long long)div) % mmod, (b * (long long)div) % mmod);
}
int pw(int a, int b) {
if (!b) return 1;
int c = pw(a, b/2);
c = (c * 1LL * c) % mmod;
if (b % 2) c = (c * 1LL * a) % mmod;
return c;
}
int mult(int a, int b, int c) {
int d = (a * 1LL * b) % mmod;
d = (d * 1LL * c) % mmod;
return d;
}
vector<int> fac;
int catalan(int n) {
int res = mult(fac[2*n], inv_mod(fac[n+1], 1), inv_mod(fac[n], 1));
return res;
}
int main()
{
int n, k;
cin >> n >> k;
fac.resize(3*n+1);
fac[0] = 1;
for (int i=1; i<=3*n; i++)
fac[i] = (fac[i-1] * 1LL * i) % mmod;
int res = pw(k+1, n);
for (int i=0; 2*i+1<=n; i++) {
res = (res - mult(catalan(i), pw(k, i), pw(k+1, n-2*i-1))) % mmod;
res = (res + mmod) % mmod;
}
printf("%d\n", res);
}
