#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
//using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
using i128 = __int128_t;
using u128 = unsigned __int128_t;
using mint = atcoder::static_modint<1000000007>;
const int mod = 998244353;
#include <chrono>
mt19937_64 rng(std::chrono::steady_clock::now().time_since_epoch().count());
int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1};
int dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};
template<class T>
bool chmin(T& a, const T& b){
    if (b < a){
        a = b;
        return true;
    }
    else { 
        return false;
    }
}
template<class T> 
bool chmax(T& a, const T& b){
    if (a < b){
        a = b;
        return true;
    }
    else {
        return false;
    }
}

void solve(){
    int n, m, k;
    cin >> n >> m >> k;
    vector<pair<int, int>> p;
    for (int i = 0; i < m; i++){
        int l, r;
        cin >> l >> r;
        l--;
        r--;
        p.push_back({l, r});
    }
    vector<mint> dp(n + 1);
    dp[0] = 1;
    for (int i = 0; i < k; i++){
        vector<mint> cnt(n + 1);
        for (int j = 0; j < n; j++){
            cnt[j + 1] = cnt[j] + dp[j];
        }
        vector<mint> imos(n + 1);
        for (int j = 0; j < m; j++){
            int l = p[j].first, r = p[j].second;
            imos[l] += cnt[r + 1] - cnt[l];
            imos[r + 1] -= cnt[r + 1] - cnt[l];
        }
        for (int j = 0; j <= n; j++){
            imos[j + 1] += imos[j];
        }
        swap(dp, imos);
    }
    cout << dp[n - 1].val() << '\n';
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t = 1;   
    while(t--){
        cout << fixed << setprecision(15);          
        solve();
    }   
}