#include<iostream>
#include<vector>
#include<string>
#include<cmath>
#include<algorithm>
#include<functional>
#include<numeric>
#include<queue>
#include<stack>
#include<map>
#include<unordered_map>
#include<set>
#include<bitset>
#include<random>

#pragma region
using namespace std;
#define FOR(i,r,n) for(ll i = (ll)(r); i < (ll)(n); i++)
#define rep(i,n) FOR(i,0LL,n)
#define RFOR(i,r,n) for(ll i=(ll)(n-1);i>=r;i--)
#define rrep(i,n) RFOR(i,0LL,n)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define COUNT(a,y,x) upper_bound(all(a), y) - lower_bound(all(a), x)
#define UNIQUE(a) sort(all(a)); a.erase(unique(all(a)), a.end())
#define pb push_back
typedef long long int ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef pair<ll, ll> pll;
typedef vector<pll> vpll;
typedef vector<string> vs;
typedef map<ll, ll> MAP;
const ll inf = 2222222222222222222LL;
const ll mod = 1000000007LL;

ll n = 0, m = 0, ans = 0, tmp = 0, ma = -inf, mi = inf;
string s;
bool ok;
ll dx[9] = { 0,1,-1,0,0,1,1,-1,-1 }, dy[9] = { 0,0,0,1,-1,1,-1,1,-1 };
#define endl '\n'
#pragma endregion
#define MAX 222222


ll le[3333], ri[3333], dp[3333][3333], sum[3333];



int main(void) {
  ios::sync_with_stdio(false); cin.tie(0);


  ll k;
  cin >> n >> m >> k;
  rep(i, m) cin >> le[i] >> ri[i];
  dp[0][1]++;
  rep(i, k) {
    FOR(j, 1, n + 1) {
      (sum[j] = sum[j - 1] + dp[i][j]) %= mod;
    }
    rep(j, m) {
      (tmp = sum[ri[j]] - sum[le[j] - 1] + mod) %= mod;
      (dp[i+1][le[j]] += tmp) %= mod;
      (dp[i + 1][ri[j] + 1] += mod - tmp) %= mod;
    }
    FOR(j, 1, n + 1) {
      (dp[i + 1][j] += dp[i + 1][j - 1]) %= mod;
    }
  }

  cout << dp[k][n] << endl;


  return 0;
}