#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const ll MOD = 1000000007;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m, K;
    cin >> n >> m >> K;
    vector<int> L(m), R(m);
    for (int i = 0; i < m; i++) {
        cin >> L[i] >> R[i];
        L[i]--;
    }

    vector<ll> dp(n + 1, 0);
    dp[0] = 1;
    vector<ll> sum(n + 1, 1);
    sum[0] = 0;
    for (int i = 0; i < K; i++) {
        vector<ll> ndp(n + 1, 0);
        for (int j = 0; j < m; j++) {
            ll s = (sum[R[j]] + MOD - sum[L[j]]) % MOD;
            (ndp[R[j]] += (MOD - s)) %= MOD;
            (ndp[L[j]] += s) %= MOD;
        }
        
        for (int j = 1; j < n; j++) {
            ndp[j] = (ndp[j - 1] + ndp[j]) % MOD;
        }

        dp = move(ndp);

        sum.assign(n + 1, 0);
        for (int j = 0; j < n; j++) {
            sum[j + 1] = (sum[j] + dp[j]) % MOD;
        }
    }
    cout << dp[n - 1] << endl;
    return 0;
}