#include <bits/stdc++.h>
using namespace std;
using PP = pair<long, long>;
const int INF = 1e9;
template <class T> T Next() { T t; cin >> t; return t; }

const int mod = 1000000007;
int n, m, k;
int l[3000];
int r[3000];
vector<int> cur;
vector<int> nxt;
vector<int> tmp;

void addmod(int& a, int b) {
  a += b;
  if (a >= mod) a -= mod;
}

int plusmod(int a, int b) {
  int ret = a + b;
  return ret >= mod ? ret - mod : ret;
}

void sub() {
  for (int i = 0; i < n; ++i) {
    tmp[i + 1] = plusmod(tmp[i], cur[i]);
  }
  
  nxt.assign(n + 1, 0);
  for (int j = 0; j < m; ++j) {
    int s = plusmod(tmp[r[j]], mod - tmp[l[j]]);
    addmod(nxt[l[j]], s);
    addmod(nxt[r[j]], mod - s);
  }

  for (int i = 0; i < n; ++i) {
    addmod(nxt[i + 1], nxt[i]); 
  }
}

int main() {
  cin >> n >> m >> k;
  for (int j = 0; j < m; ++j) {
    cin >> l[j] >> r[j];
    --l[j];
  }
  
  cur.resize(n + 1);
  nxt.resize(n + 1);
  tmp.resize(n + 1);
  
  cur[0] = 1;
  for (int z = 0; z < k; ++z) {
    sub();
    swap(cur, nxt);
  }
  
  cout << cur[n - 1] << endl;
}