#include <iostream>
#include <algorithm>
#include <vector>
#include <map>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); i++)

const int MOD = 1e9 + 7;

struct mint {
    int n;
    mint(int n_ = 0) : n(n_) {}
};

mint operator+(mint a, mint b) { a.n += b.n; if (a.n >= MOD) a.n -= MOD; return a; }
mint operator-(mint a, mint b) { a.n -= b.n; if (a.n < 0) a.n += MOD; return a; }
mint operator*(mint a, mint b) { return (long long)a.n * b.n % MOD; }
mint &operator+=(mint &a, mint b) { return a = a + b; }
mint &operator-=(mint &a, mint b) { return a = a - b; }
mint &operator*=(mint &a, mint b) { return a = a * b; }

mint dp[3001];

int main() {
  int N, M, K;
  cin >> N >> M >> K;
  vector<int> L(M), R(M);
  REP(i, M) {
    cin >> L[i] >> R[i];
    L[i]--;
  }
  dp[0] = 1;
  REP(i, K) {
    mint X[3001];
    X[0] = 0;
    REP(j, N) {
      X[j + 1] = X[j] + dp[j];
    }
    REP(j, N + 1) dp[j] = 0;
    REP(j, M) {
      dp[L[j]] += X[R[j]] - X[L[j]];
      dp[R[j]] -= X[R[j]] - X[L[j]];
    }
    REP(j, N) dp[j + 1] += dp[j];
  }
  cout << dp[N - 1].n << '\n';
}