/* ---------- STL Libraries ---------- */
// IO library
#include <cstdio>
#include <fstream>
#include <iomanip>
#include <ios>
#include <iostream>

// algorithm library
#include <algorithm>
#include <cmath>
#include <numeric>
#include <random>
#include <cstring>

// container library
#include <array>
#include <bitset>
#include <deque>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <string>
#include <tuple>
#include <vector>
#include <stack>

/* ---------- Namespace ---------- */
using namespace std;

/* ---------- Type ---------- */
using ll = long long;
#define int ll
#define P pair<ll, ll>

/* ---------- Constants  */
const double PI = 3.141592653589793238462643383279;
const ll MOD = 1e9 + 7;
const int INF = 1LL << 55;

/* v-v-v-v-v-v-v-v-v Main Part v-v-v-v-v-v-v-v-v */
signed main() {
    // dp[i][j]: i回の移動でj階に移動する場合の数
    // [dp[i+1][Li], dp[i+1][Ri]] <- [dp[i][Li], dp[i][Ri]]

    int N, M, K;
    cin >> N >> M >> K;

    vector<int> L(M);
    vector<int> R(M);
    for (int i = 0; i < M; i++) {
        cin >> L[i] >> R[i];
        L[i]--; R[i]--;
    }

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

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

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

        for (int j = 0; j < N; j++) (dp[i+1][j+1] += dp[i+1][j]) %= MOD;
    }

    cout << dp[K][N - 1] << endl;

    return 0;
}