#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
inline void add(int &x, int y) {
  x += y;
  if (x >= mod) x -= mod;
}
inline void sub(int &x, int y) {
  x -= y;
  if (x < 0) x += mod;
}
inline int subb(int x, int y) {
  x -= y;
  if (x < 0) x += mod;
  return x;
}
signed main() {
  ios::sync_with_stdio(false); cin.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  vector<int> l(m), r(m);
  for (int i = 0; i < m; i++) {
    cin >> l[i] >> r[i];
  }
  vector<vector<int>> dp(k + 1, vector<int>(n + 2));
  dp[0][1] = 1; dp[0][2] = -1;
  for (int i = 0; i <= k; i++) {
    for (int j = 1; j <= n; j++) {
      add(dp[i][j], dp[i][j - 1]);
    }
    if (i == k) break;
    for (int j = 1; j <= n; j++) {
      add(dp[i][j], dp[i][j - 1]);
    }
    for (int j = 0; j < m; j++) {
      int x = subb(dp[i][r[j]], dp[i][l[j] - 1]);
      add(dp[i + 1][l[j]], x);
      sub(dp[i + 1][r[j] + 1], x);
    }
  } 
  cout << dp[k][n] << endl;
  return 0;
}