#include <bits/stdc++.h>
  
using namespace std;
  
#define rep(i,n) REP(i,0,n)
#define REP(i,s,e) for(int i=(s); i<(int)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for(int i=(int)(s-1); i>=(int)(e); i--)
#define pb push_back
#define all(r) r.begin(),r.end()
#define rall(r) r.rbegin(),r.rend()
#define fi first
#define se second
  
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
const int INF = 1e9;
const ll MOD = 1e9 + 7;
double EPS = 1e-8;


const int MAX_N = 3010;
ll dp[MAX_N][2];

int main(){
    int n, m, k;
    cin >> n >> m >> k;
    vi L(m), R(m);
    rep(i, m) {
        cin >> L[i] >> R[i];
    }
    int cur = 0, nxt = 1;
    REP(i, 1, MAX_N) dp[i][cur] = 1LL;
    rep(_, k) {
        rep(i, MAX_N) dp[i][nxt] = 0LL;
        rep(i, m) {
            ll cnt = (dp[R[i]][cur] - dp[L[i]-1][cur] + MOD) % MOD;
            (dp[L[i]][nxt] += cnt) %= MOD;
            (dp[R[i]+1][nxt] += MOD-cnt) %= MOD;
        }
        REP(i, 1, MAX_N) (dp[i][nxt] += dp[i-1][nxt]) %= MOD;
        REP(i, 1, MAX_N) (dp[i][nxt] += dp[i-1][nxt]) %= MOD;
        swap(cur, nxt);
        // rep(i, n+1) {
        //     cout << " " << dp[i][cur];
        // }
        // cout << endl;
    }
    // rep(i, n+1) cout << " " << dp[i][cur];
    // cout << endl;
    cout << (dp[n][cur] - dp[n-1][cur] + MOD) % MOD << endl;
    return 0;
}