#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

template<unsigned P> struct ModInt {
  using M = ModInt;
  unsigned v;
  ModInt() : v(0) {}
  template<class Z> ModInt(Z x) : v(x >= 0 ? x % P : -x % P ? P - -x % P : 0) {}
  constexpr ModInt(unsigned v, int) : v(v) {}
  static constexpr unsigned p() { return P; }
  M operator+() const { return *this; }
  M operator-() const { return {v ? P - v : 0, 0}; }
  explicit operator bool() const noexcept { return v; }
  bool operator!() const noexcept { return !(bool) *this; }
  M operator*(M r) const { return M(*this) *= r; }
  M operator/(M r) const { return M(*this) /= r; }
  M operator+(M r) const { return M(*this) += r; }
  M operator-(M r) const { return M(*this) -= r; }
  bool operator==(M r) const { return v == r.v; }
  bool operator!=(M r) const { return !(*this == r); }
  M& operator*=(M r) { v = (uint64_t) v * r.v % P; return *this; }
  M& operator/=(M r) { return *this *= r.inv(); }
  M& operator+=(M r) { v = r.v < P - v ? v + r.v : v - (P - r.v); return *this; }
  M& operator-=(M r) { v = r.v <= v ? v - r.v : v + (P - r.v); return *this; }
  M inv() const {
    int a = v, b = P, x = 1, u = 0;
    while (b) {
      int q = a / b;
      swap(a -= q * b, b);
      swap(x -= q * u, u);
    }
    assert(a == 1);
    return x;
  }
  template<class Z> M pow(Z n) const {
    n = n >= 0 ? n % (P - 1) : P - 1 - -n % (P - 1);
    M res = 1;
    for (M a = *this; n; a *= a, n >>= 1) if (n & 1) res *= a;
    return res;
  }
  template<class Z> friend M operator*(Z l, M r) { return M(l) *= r; }
  template<class Z> friend M operator/(Z l, M r) { return M(l) /= r; }
  template<class Z> friend M operator+(Z l, M r) { return M(l) += r; }
  template<class Z> friend M operator-(Z l, M r) { return M(l) -= r; }
  friend ostream& operator<<(ostream& os, M r) { return os << r.v; }
  friend istream& operator>>(istream& is, M& r) { lint x; is >> x; r = x; return is; }
  template<class Z> friend bool operator==(Z l, M r) { return M(l) == r; }
  template<class Z> friend bool operator!=(Z l, M r) { return !(l == r); }
};
using Mint = ModInt<(unsigned) 1e9 + 7>;

int main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  int n, m, k; cin >> n >> m >> k;
  V<> l(m), r(m); for (int i = 0; i < m; ++i) cin >> l[i] >> r[i], --l[i];
  V<Mint> dp(n);
  dp[0] = 1;
  for (int i = 0; i < k; ++i) {
    V<Mint> c(n + 1);
    for (int i = 0; i < n; ++i) {
      c[i + 1] = c[i] + dp[i];
    }
    V<Mint> ndp(n);
    for (int j = 0; j < m; ++j) {
      ndp[l[j]] += c[r[j]] - c[l[j]];
      if (r[j] < n) ndp[r[j]] -= c[r[j]] - c[l[j]];
    }
    for (int i = 0; i + 1 < n; ++i) {
      ndp[i + 1] += ndp[i];
    }
    swap(dp, ndp);
  }
  cout << dp.back() << '\n';
}