#include <bits/stdc++.h>
#define rep(i,n) for(ll i=0, i##_len=(n); i<i##_len; ++i)
#define REP(i,num,n) for(ll i=num, i##_len=(n); i<i##_len; ++i)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((ll)(x).size())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
#define MEMSET(v, h) memset((v), h, sizeof(v))
#define pb push_back
#define mp make_pair
#define y0 y3487465
#define y1 y8687969
#define j0 j1347829
#define j1 j234892
typedef long long ll;
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; }
using namespace std;

int main(){
  ll N,M,K;
  cin >> N >> M >> K;
  vector<ll> L(M),R(M);
  ll MOD = 1000000007;

  rep(i,M) cin >> L[i] >> R[i];

  vector<ll> cur(N+2,0);
  vector<ll> next(N+2,0);
  
  cur[1] = 1;
  REP(i,1,K+1){
    next.assign(N+2,0);
    vector<ll> add(N+1,0);
    rep(j,N) add[j+1] = (add[j] + cur[j+1]) % MOD;
    rep(j,M){
      ll left = L[j];
      ll right = R[j];
      ll sum = (add[right] - add[left-1] + MOD) % MOD;
      
      next[left] += sum, next[left] %= MOD;
      next[right+1] += MOD - sum, next[right+1] %= MOD;
    }
    
    rep(j,N)next[j+1] += next[j], next[j+1] %= MOD;
    swap(cur, next);
  }
  
  cout << cur[N] << endl;


  return 0;
}