#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;
const int MAX_N = 3010;

ll dp[MAX_N];
ll RUI[MAX_N];
ll D[MAX_N];
int L[MAX_N];
int R[MAX_N];

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

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

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

  for (int i = 0; i < K; ++i) {
    memset(RUI, 0, sizeof(RUI));

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

    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]) % MOD;

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

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

  cout << dp[N] << endl;

  return 0;
}