#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
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];

    vector<long long> v(n+1, 0);
    v[1] = 1;
    while(--k >= 0){
        vector<long long> sum(n+1, 0);
        for(int i=0; i<n; ++i)
            sum[i+1] = (sum[i] + v[i+1]) % MOD;

        vector<long long> v2(n+2, 0);
        for(int i=0; i<m; ++i){
            long long tmp = (sum[r[i]] - sum[l[i]-1] + MOD) % MOD;
            v2[l[i]] += tmp;
            v2[l[i]] %= MOD;
            v2[r[i]+1] += -tmp + MOD;
            v2[r[i]+1] %= MOD;
        }
        for(int i=1; i<=n; ++i){
            v2[i+1] += v2[i];
            v2[i+1] %= MOD;
        }
        v = move(v2);
        v.resize(n+1);
    }
    cout << v[n] << endl;

    return 0;
}