#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <functional>

using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;

#define repi(i,a,b) for(ll i=a;i<b;i++)
#define rep(i,a) repi(i,0,a)
#define rrep(i,a) for(ll i=a-1;i>=0;i--)
#define MOD 1000000007

int main(){
  ll N, M, K;
  cin >> N >> M >> K;
  vector<P> elev;
  rep(_, M){
    ll L, R;
    cin >> L >> R;
    elev.emplace_back(L-1, R-1);
  }

  vector<vector<ll>> ans(2, vector<ll>(N, 0));
  ans[0][0] = 1;
  rep(k, K){
    rep(i, N-1) ans[k%2][i+1] = (ans[k%2][i] + ans[k%2][i+1]) % MOD;
    rep(i, N) ans[(k+1)%2][i] = 0;
    for(auto& e: elev){
      ll sum = e.first ? ans[k%2][e.second] - ans[k%2][e.first-1] : ans[k%2][e.second];
      ans[(k+1)%2][e.first] = (ans[(k+1)%2][e.first] + sum + MOD) % MOD;
      if(e.second + 1 < N)
        ans[(k+1)%2][e.second+1] = (ans[(k+1)%2][e.second+1] - sum + MOD) % MOD;
    }
    rep(i, N-1) ans[(k+1)%2][i+1] = (ans[(k+1)%2][i+1] + ans[(k+1)%2][i]) % MOD;
  }
  cout << ans[K%2][N-1] << endl;
  return 0;
}