// #define _GLIBCXX_DEBUG // for STL debug (optional)
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;

#define debug(...) fprintf(stderr, __VA_ARGS__)
#define int long long int
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
typedef pair<int, int> pii;
typedef long long ll;
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const ll INF = 1001001001001001LL;
const ll MOD = 1000000007LL;

signed main() {
    int N, M, K; cin >> N >> M >> K;
    vector<int> L(M), R(M);
    // (L, R]
    for(int i=0; i<M; i++) {
        cin >> L[i] >> R[i];
        L[i]--;
    }
    
    vector<int> cur(N+2), nxt(N+2);

    for(int i=1; i<=N; i++) {
        cur[i] = 1;
    }

    for(int i=0; i<K; i++) {
        for(int j=0; j<M; j++) {
            int val = cur[ R[j] ] - cur[ L[j] ];
            // fprintf(stderr, "i = %lld, j = %lld, val = %lld\n", i, j, val);
            (nxt[ L[j] + 1 ] += val      ) %= MOD;
            (nxt[ R[j] + 1 ] += MOD - val) %= MOD;
        }

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

        swap(cur, nxt);
        fill(nxt.begin(), nxt.end(), 0LL);
    }
    cout << (cur[N] - cur[N-1] + MOD) % MOD << endl;
    return 0;
}