#include <atcoder/all>
using namespace atcoder;
#include <bits/stdc++.h>
#define itr(x,c) for(auto x=c.begin();x!=c.end();x++)
#define ritr(x,c) for(auto x=c.rbegin();x!=c.rend();x++)
#define all(a) (a.begin()),(a.end())
#define rall(a) (a.rbegin()),(a.rend())
using namespace std;
using ll=long long;
using pll=pair<ll,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;}
template<class T>istream& operator >> (istream& is, vector<T>& v) { for(T& x:v) is >> x; return is; }
template<class T>ostream& operator << (ostream& os, const vector<T>& v) {for(int i=0;i<v.size();i++) {os << v[i] << (i+1 == v.size() ? "":" ");} return os;}

template<class... A> void pt()      { std::cout << "\n"; }
template<class... A> void pt_rest() { std::cout << "\n"; }
template<class T, class... A> void pt_rest(const T& first, const A&... rest) { std::cout << " " << first; pt_rest(rest...); }
template<class T, class... A> void pt(const T& first, const A&... rest)      { std::cout << first; pt_rest(rest...); }

template<class T1, class T2>istream& operator >> (istream& is, pair<T1,T2>& p) { is >> p.first >> p.second; return is; }

static const ll INF=1e18+7;
static const ll MAX=101010;
static const ll MOD=1e9+7;
static const double PI=acos(-1);
static const double EPS=1e-10;
//static const ll MOD=998244353;

using v1d=vector<modint1000000007>;
using v2d=vector<v1d>;
using v3d=vector<v2d>;
using v4d=vector<v3d>;



int main(void) {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  ll i,j,k;
  
  ll N,M,K;cin>>N>>M>>K;
  vector<ll> l(M),r(M);
  for(i=0;i<M;i++)cin>>l[i]>>r[i];
  
  v2d dp(K+1,v1d(N+1,0));
  dp[0][1]=1;
  for(k=0;k<K;k++){
    v1d s(N+1,0);
    for(i=1;i<=N;i++)s[i]=s[i-1]+dp[k][i];
    
    v1d c(N+2,0);
    for(i=0;i<M;i++){
      modint1000000007 t=s[r[i]]-s[l[i]-1];
      c[l[i]]+=t;
      c[r[i]+1]-=t;
    }
    for(i=1;i<=N;i++)c[i]+=c[i-1];
    
    for(i=1;i<=N;i++)dp[k+1][i]=c[i];
  }
  
  pt(dp[K][N].val());
  
}