#include <iostream>
#include <vector>
using namespace std;
const int MOD = 1000000007;

int main() {
    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<long long> cur(N+1, 0), next(N+1, 0);
    cur[0] = 1;
    for (int k = 0; k < K; ++k) {
        vector<long long> sum(N+1, 0);
        for (int i = 0; i < N; ++i) sum[i+1] = (sum[i] + cur[i]) % MOD;
        next.assign(N+1, 0);
        for (int i = 0; i < M; ++i) {
            long long add = (sum[R[i]] - sum[L[i]] + MOD) % MOD;
            next[L[i]] += add; next[L[i]] %= MOD;
            next[R[i]] += MOD - add; next[R[i]] %= MOD;
        }
        for (int i = 0; i < N; ++i) next[i+1] += next[i], next[i+1] %= MOD;
        swap(cur, next);
    }
    cout << cur[N-1] << endl;
}