#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 + 1, 0));
    dp[0][0] = 1;

    for (int i = 1; i <= K; i++) {
        vector<long long> sum(N + 1, 0);
        sum[0] = dp[i - 1][0];
        for (int j = 1; j <= N; j++) {
            sum[j] += sum[j - 1] + dp[i - 1][j - 1];
            sum[j] %= MOD;
        }

        for (int j = 0; j < M; j++) {
            int l = L[j];
            int r = R[j] + 1;
            long long s = (sum[r] - sum[l] + MOD) % MOD;
            dp[i][l] = (dp[i][l] + s) % MOD;
            dp[i][r] = (dp[i][r] - s + MOD) % MOD;
        }

        for (int j = 1; j <= N; j++) {
            dp[i][j] += dp[i][j - 1];
            dp[i][j] %= MOD;
        }
    }

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