#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;

const ll MOD = 1000000007LL;
ll dp[3005][3005];
ll sum[3005];
ll nxt[3005];

int main(){
  int N, M, K;
  cin >> N >> M >> K;
  vector<vector<int>> v;
  rep(i,M){
    int l, r;
    cin >> l >> r;
    v.push_back({l,r});
  }

  dp[0][1] = 1;
  rep(i,K){
    sum[0] = 0;
    REP(j,1,3005) sum[j] = sum[j-1] + dp[i][j];
    rep(j,3005) nxt[j] = 0;
    rep(j,v.size()){
      ll s = sum[v[j][1]] - sum[v[j][0]-1];
      nxt[v[j][0]] += s;
      nxt[v[j][1]+1] -= s;
    }
    ll base = 0;
    rep(j,3005){
      base += nxt[j];
      dp[i+1][j] = base % MOD;
    }
  }

  cout << dp[K][N] << endl;
  
  return 0;
}