#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007

int main(void) {
    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]--;
        R[i]--;
    }

    vector<vector<long long> > dp(K + 1, vector<long long>(N, 0));
    dp[0][0] = 1;

    for (int i = 1; i <= K; i++) {
        for (int k = 0; k < M; k++) {
            long long sum = 0;
            for (int l = L[k]; l <= R[k]; l++) {
                sum += dp[i - 1][l] % mod;
            }
            sum %= mod;
            for (int l = L[k]; l <= R[k]; l++) {
                dp[i][l] = (dp[i][l] + sum) % mod;
            }
        }
    }

    cout << dp[K][N - 1] << endl;
    return 0;
}