import java.io.PrintWriter import java.util.* import kotlin.math.* fun PrintWriter.solve() { val n = nextInt() val k = nextLong() val customers = mutableListOf>() for (i in 0 until n) { val l = nextInt() val r = nextInt() customers.add(l to r) } customers.sortBy { it.first } val lst = mutableListOf() var compl = ModInt(1) for ((l, r) in customers) { var ng = 0 var ok = lst.size while (ok - ng > 1) { val mid = (ng + ok) / 2 if (lst[mid] <= l) { ng = mid } else { ok = mid } } if (lst.size > 0 && lst[0] > l) { ok = 0 } compl *= ModInt(k - (lst.size - ok)) lst.add(r) lst.sort() } val ans = ModInt(k).pow(n.toLong()) - compl println(ans) } // region ModInt class ModInt(x: Long) { companion object { const val MOD = 1000000007L //const val MOD = 998244353L } constructor(y: Int) : this(y.toLong()) val x = (x % MOD + MOD) % MOD operator fun plus(other: ModInt): ModInt { return ModInt(x + other.x) } operator fun minus(other: ModInt): ModInt { return ModInt(x - other.x) } operator fun times(other: ModInt): ModInt { return ModInt(x * other.x) } operator fun div(other: ModInt): ModInt { return this * other.inv() } fun pow(exp: Long): ModInt { if (exp == 0L) return ModInt(1L) var a = pow(exp shr 1) a *= a if (exp and 1L == 0L) return a return this * a } fun inv(): ModInt { return this.pow(MOD - 2) } override fun equals(other: Any?): Boolean { if (this === other) return true if (javaClass != other?.javaClass) return false other as ModInt if (x != other.x) return false return true } override fun hashCode(): Int { return x.hashCode() } override fun toString(): String { return "$x" } } fun Long.toModInt(): ModInt { return ModInt(this) } fun Int.toModInt(): ModInt { return ModInt(this) } fun binomSimple(n: Long, k: Long): ModInt { var numer = ModInt(1) var denom = ModInt(1) for (i in 0 until k) { numer *= ModInt(n - i) denom *= ModInt(k - i) } return numer / denom } // endregion fun main() { val writer = PrintWriter(System.out, false) writer.solve() writer.flush() } // region Scanner private var st = StringTokenizer("") private val br = System.`in`.bufferedReader() fun next(): String { while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine()) return st.nextToken() } fun nextInt() = next().toInt() fun nextLong() = next().toLong() fun nextLine() = br.readLine() fun nextDouble() = next().toDouble() // endregion