#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <vector>
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
//#define cerr if(false) cerr
#define show(...) cerr << #__VA_ARGS__ << " = ",debug(__VA_ARGS__);
using namespace std;
using ll = long long;
using pii = pair<int,int>;
template<typename T, typename S>
ostream &operator<<(ostream &os, pair<T, S> a){
    os << '(' << a.first << ',' << a.second << ')';
    return os;
}
template<typename T>
ostream &operator<<(ostream &os, vector<T> v){
    for(auto x:v)os << x << ' ';
    return os;
}
void debug(){cerr << '\n';}
template<typename H, typename... T>
void debug(H a, T... b){
    cerr << a;
    if(sizeof...(b))cerr << ", ";
    debug(b...);
}
ll mod = 1e9+7;
ll dp[3005][3005];
int main(){
    int n,m,k;
    cin >> n >> m >> k;
    vector<int>L(m),R(m);
    rep(i,m){
        cin >> L[i] >> R[i];
    }
    dp[0][1] = 1;
    for(int i = 0; i < k; i++){
        for(int j = 0; j < n; j++){
            dp[i][j+1] += dp[i][j];
            dp[i][j+1] %= mod;
        }
        for(int j = 0; j < m; j++){
            ll sum = (dp[i][R[j]]-dp[i][L[j]-1]+mod)%mod;
            dp[i+1][L[j]] = (dp[i+1][L[j]] + sum) % mod;
            dp[i+1][R[j]+1] = (dp[i+1][R[j]+1] - sum + mod) % mod;
        }
        for(int j = 0; j < n; j++){
            dp[i+1][j+1] += dp[i+1][j];
            dp[i+1][j+1] %= mod;
        }
    }
    cout << dp[k][n] << endl;
}