#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<ll, ll> p_ll;

template<class T>
void debug(T itr1, T itr2) { auto now = itr1; while(now<itr2) { cout << *now << " "; now++; } cout << endl; }
#define repr(i,from,to) for (int i=(int)from; i<(int)to; i++)
#define all(vec) vec.begin(), vec.end()
#define rep(i,N) repr(i,0,N)
#define per(i,N) for (int i=(int)N-1; i>=0; i--)

const ll MOD = pow(10,9)+7;
const ll LLINF = pow(2,61)-1;
const int INF = pow(2,30)-1;

vector<ll> fac;
void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; }
ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; }
ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; }
ll gcd(ll a, ll b) { if (a<b) swap(a,b); return b==0 ? a : gcd(b, a%b); }
ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }

struct elevator { ll l, r; };

int main() {
  ll N, M, K; cin >> N >> M >> K;
  elevator e[M]; rep(i,M){ cin >> e[i].l >> e[i].r; e[i].l--; e[i].r--; }
  ll result[N] = {}; result[0] = 1;
  rep(i,K) {
    ll rsum[N+1] = {}; rep(i,N) rsum[i+1] = (rsum[i] + result[i]) % MOD;
    ll rimos[N+1] = {};
    rep(i,M) { 
      ll diff = (rsum[e[i].r+1]-rsum[e[i].l]+MOD) % MOD;
      rimos[e[i].l] = (rimos[e[i].l]+diff) % MOD;
      rimos[e[i].r+1] = (rimos[e[i].r+1]-diff+MOD) % MOD;
    }
    rep(i,N) result[i] = i==0 ? rimos[i] : (result[i-1] + rimos[i]) % MOD;
    // debug(rsum,rsum+(N+1));
    // debug(rimos,rimos+(N+1));
    // debug(result,result+N);
  }
  cout << result[N-1] << endl;
  return 0;
}