#include <bits/stdc++.h>
#include <math.h>

#include <algorithm>
#include <array>
#include <atcoder/all>
#include <bitset>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <sstream>
#include <vector>

using namespace std;
using namespace atcoder;

using Graph = vector<vector<int>>;

using ll = long long;
typedef pair<ll, ll> P_ll;
typedef pair<int, int> P;

const ll INF_ll = 1e17;
const int INF = 1e8;
template <class T>
bool chmax(T& a, const T& b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T& a, const T& b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename T>
using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;

int main() {
  int N, M, K;
  cin >> N >> M >> K;
  vector<ll> L(M), R(M);
  for (int i = 0; i < M; i++) {
    cin >> L[i] >> R[i];
    L[i]--;
    R[i]--;
  }
  vector<modint1000000007> dp(N, 0);
  vector<modint1000000007> sumdp(N, 1);
  dp[0] = 1;
  for (int _ = 0; _ < K; _++) {
    vector<modint1000000007> imos(N + 1, 0);
    for (int i = 0; i < M; i++) {
      modint1000000007 x = sumdp[R[i]];
      if (L[i] > 0) {
        x -= sumdp[L[i] - 1];
      }
      imos[L[i]] += x;
      imos[R[i] + 1] -= x;
    }
    vector<modint1000000007> nextdp(N, 0);
    modint1000000007 now = 0;
    for (int i = 0; i < N; i++) {
      now += imos[i];
      nextdp[i] += now;
    }
    vector<modint1000000007> nextsum(N, 0);
    nextsum[0] = nextdp[0];
    for (int i = 1; i < N; i++) {
      nextsum[i] = nextsum[i - 1] + nextdp[i];
    }
    swap(nextdp, dp);
    swap(nextsum, sumdp);
  }
  cout << dp[N - 1].val() << endl;

  return 0;
}