#include <bits/stdc++.h>
using namespace std;

template <int MOD_> struct modnum {
	static constexpr int MOD = MOD_;
	static_assert(MOD_ > 0, "MOD must be positive");

private:
	using ll = long long;

	int v;

	static int minv(int a, int m) {
		a %= m;
		assert(a);
		return a == 1 ? 1 : int(m - ll(minv(m, a)) * ll(m) / a);
	}

public:

	modnum() : v(0) {}
	modnum(ll v_) : v(int(v_ % MOD)) { if (v < 0) v += MOD; }
	explicit operator int() const { return v; }
	friend std::ostream& operator << (std::ostream& out, const modnum& n) { return out << int(n); }
	friend std::istream& operator >> (std::istream& in, modnum& n) { ll v_; in >> v_; n = modnum(v_); return in; }

	friend bool operator == (const modnum& a, const modnum& b) { return a.v == b.v; }
	friend bool operator != (const modnum& a, const modnum& b) { return a.v != b.v; }

	modnum inv() const {
		modnum res;
		res.v = minv(v, MOD);
		return res;
	}
	friend modnum inv(const modnum& m) { return m.inv(); }
	modnum neg() const {
		modnum res;
		res.v = v ? MOD-v : 0;
		return res;
	}
	friend modnum neg(const modnum& m) { return m.neg(); }

	modnum operator- () const {
		return neg();
	}
	modnum operator+ () const {
		return modnum(*this);
	}

	modnum& operator ++ () {
		v ++;
		if (v == MOD) v = 0;
		return *this;
	}
	modnum& operator -- () {
		if (v == 0) v = MOD;
		v --;
		return *this;
	}
	modnum& operator += (const modnum& o) {
		v += o.v;
		if (v >= MOD) v -= MOD;
		return *this;
	}
	modnum& operator -= (const modnum& o) {
		v -= o.v;
		if (v < 0) v += MOD;
		return *this;
	}
	modnum& operator *= (const modnum& o) {
		v = int(ll(v) * ll(o.v) % MOD);
		return *this;
	}
	modnum& operator /= (const modnum& o) {
		return *this *= o.inv();
	}

	friend modnum operator ++ (modnum& a, int) { modnum r = a; ++a; return r; }
	friend modnum operator -- (modnum& a, int) { modnum r = a; --a; return r; }
	friend modnum operator + (const modnum& a, const modnum& b) { return modnum(a) += b; }
	friend modnum operator - (const modnum& a, const modnum& b) { return modnum(a) -= b; }
	friend modnum operator * (const modnum& a, const modnum& b) { return modnum(a) *= b; }
	friend modnum operator / (const modnum& a, const modnum& b) { return modnum(a) /= b; }
};

template <typename T> T pow(T a, long long b) {
	assert(b >= 0);
	T r = 1; while (b) { if (b & 1) r *= a; b >>= 1; a *= a; } return r;
}

using num = modnum<int(1e9) + 7>;

const int MAXN = 1.1e5;
const int MAXK = 11;

struct segtree {
	static const int S = 1<<18;
	struct seg_node {
		num sum;
		num m;
		num a;
	} seg[S*2];

	void affine(int i, num m, num a, int len) {
		if (m == 1 && a == 0) return;
		auto& n = seg[i];
		n.sum *= m;
		n.sum += a * len;
		n.m *= m;
		n.a *= m;
		n.a += a;
	}

	void propagate(int i, int len) {
		assert(i < S);
		auto& n = seg[i];
		if (n.m != 1 || n.a != 0) {
			affine(2*i, n.m, n.a, len/2);
			affine(2*i+1, n.m, n.a, len/2);
			n.m = 1, n.a = 0;
		}
	}

	void update(int i, int l, int r, int ql, int qr, num m, num a) {
		if (qr <= l || r <= ql) return; 
		if (ql <= l && r <= qr) {
			affine(i, m, a, r-l);
		} else {
			propagate(i, r-l);
			int md = (l+r)/2;
			update(2*i, l, md, ql, qr, m, a);
			update(2*i+1, md, r, ql, qr, m, a);
			seg[i].sum = seg[2*i].sum + seg[2*i+1].sum;
		}
	}

	num query(int i, int l, int r, int ql, int qr) {
		if (qr <= l || r <= ql) return 0; 
		if (ql <= l && r <= qr) {
			return seg[i].sum;
		} else {
			propagate(i, r-l);
			int md = (l+r)/2;
			return query(2*i, l, md, ql, qr) + query(2*i+1, md, r, ql, qr);
		}
	}

	void update(int ql, int qr, num m, num a) {
		update(1, 0, S, ql, qr, m, a);
	}

	num query(int ql, int qr) {
		return query(1, 0, S, ql, qr);
	}
} segs[MAXK];

int N, K;
pair<int, int> S[MAXN];

num stirling[MAXK][MAXK];

int main() {
	ios::sync_with_stdio(0), cin.tie(0);

	cin >> N >> K;
	for (int i = 0; i < N; i++) {
		int l, r; cin >> l >> r;
		S[i] = {l,r};
	}
	sort(S, S+N);

	segs[0].update(0, 1, 1, 1);
	for (int i = 0; i < N; i++) {
		int l, r; tie(l, r) = S[i];

		for (int k = 0; k <= K; k++) {
			segs[k].update(r, r+1, 1, segs[k].query(0, r));
			if (k >= 1) {
				segs[k].update(r, r+1, 1, segs[k-1].query(0, l));
			}
			segs[k].update(r+1, 2*N+1, 2, 0);
		}
	}

	stirling[0][0] = 1;
	for (int i = 1; i <= K; i++) {
		for (int j = 1; j <= i; j++) {
			stirling[i][j] = stirling[i-1][j-1] + stirling[i-1][j] * j;
		}
	}

	num ans = 0;
	num fact = 1;
	for (int k = 1; k <= K; k++) {
		num tot = segs[k].seg[1].sum;

		fact *= k;
		ans += fact * tot * stirling[K][k];
	}
	cout << ans << '\n';

	return 0;
}