#include <bits/stdc++.h>
using namespace std;

long long mod = 1e9+7;

void calc_cum(vector<long long> & vec){
    int n = vec.size();
    for (int i = 1; i < n; ++i) {vec[i] += vec[i - 1]; vec[i] %= mod;}
}

long long solve(int N, int M, int K, const vector<int> & Ls, const vector<int> & Rs){
    vector<long long> imos(N + 2, 0);
    vector<long long> new_imos(N + 2, 0);
    imos[1] = 1LL;
    while (K--){
        calc_cum(imos);
        new_imos.assign(N + 2, 0);
        for (int m = 0; m < M; ++m){
            long long cum = (imos[Rs[m]] - imos[Ls[m] - 1] + mod) % mod;
            new_imos[Ls[m]] = (new_imos[Ls[m]] + cum) % mod;
            new_imos[Rs[m] + 1] = (new_imos[Rs[m] + 1] + mod - cum) % mod;
        }
        calc_cum(new_imos);
        swap(imos, new_imos);
    }
    return imos[N];
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N, M, K;
    cin >> N >> M >> K;
    vector<int> Ls(M, 0);
    vector<int> Rs(M, 0);
    for (int i = 0; i < M; ++i) cin >> Ls[i] >> Rs[i];
    cout << solve(N, M, K, Ls, Rs) << endl;
    return 0;
}