#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
int main() {
    int n, m, k; cin >> n >> m >> k;
    vector<long long> dp(n+2, 0), sw(n+2, 0);
    dp[n+1] = 1;
    vector<int> l(m), r(m);
    for (int i = 0; i < m; i++) cin >> l[i] >> r[i];
    for (int ni = 0; ni < k; ni++) {
        sw.assign(n+2, 0);
        for (int i = 0; i < m; i++) {
            long long t = (mod + dp[r[i]+1] - dp[l[i]]) % mod;
            sw[r[i]+1] = (mod + sw[r[i]+1] - t) % mod;
            sw[l[i]] = (mod + sw[l[i]] + t) % mod;
        }
        for (int i = 0; i <= n; i++) {
            sw[i+1] = (sw[i+1] + sw[i]) % mod;
        }
        dp.assign(n+2, 0);
        for (int i = 0; i <= n; i++) {
            dp[i+1] = (dp[i] + sw[i]) % mod;
        }
    }
    cout << sw[1] << endl;
    return 0;
}