const val MOD = 1000000007L
fun power(base: Long, exp: Long): Long {
    return when(exp) {
        0L -> 1L
        1L -> base % MOD
        else -> power(base * base % MOD, exp shr 1) * power(base, exp and 1) % MOD
    }
}
fun main() {
    val (n, k) = readLine()!!.trim().split(' ').map(String::toLong)
    val sumK = (k % MOD) * ((k + 1) % MOD) % MOD * power(2, MOD - 2) % MOD
    var result = 1L
    for (i in 0 until n) {
        result = result * (sumK + k % MOD) % MOD
    }
    println((result - power(sumK, n) + MOD) % MOD)
}