#include <stdio.h>
constexpr int kN = int(2E6 + 10), kMod = 1000000007;
typedef long long int ll;

ll a[kN], s[kN];
int main() {
	int n, p;
	ll ans = 0;
	scanf("%d%d", &n, &p);
	a[1] = 0, a[2] = 1;
	for (int i = 3; i <= n; i++) a[i] = (a[i - 1] * p + a[i - 2]) % kMod;
	s[1] = 0;
	for (int i = 2; i <= n; i++) s[i] = (s[i - 1] + a[i]) % kMod;
	for (int i = 1; i <= n; i++) ans += a[i] * s[i] % kMod;
	printf("%lld\n", ans % kMod);
}