#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

const ll MOD = 1000000007;

int main() {
  int N, M, K;
  cin >> N >> M >> K;

  vector<int> L(M);
  vector<int> R(M);

  for (int i = 0; i < M; ++i) {
    cin >> L[i] >> R[i];
  }

  ll dp[N + 1];
  memset(dp, 0, sizeof(dp));
  dp[1] = 1;

  for (int i = 0; i < K; ++i) {
    ll RUI[N + 1];
    memset(RUI, 0, sizeof(RUI));

    for (int j = 1; j <= N; ++j) {
      RUI[j] = dp[j] + RUI[j - 1];
      RUI[j] %= MOD;
    }

    ll D[N + 1];
    memset(D, 0, sizeof(D));

    for (int j = 0; j < M; ++j) {
      int l = L[j];
      int r = R[j];
      ll sum = RUI[r] - RUI[l - 1];

      D[l] += sum;
      D[r + 1] -= sum;
    }

    ll sum = 0;
    for (int j = 1; j <= N; ++j) {
      sum += D[j];
      sum %= MOD;
      dp[j] = sum;
    }
  }

  cout << dp[N] << endl;

  return 0;
}