#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using ll =  long long ;
using P = pair<int,int> ;
using pll = pair<ll,ll>;
constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
constexpr int MOD = 1000000007;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n,m,k;
    cin >> n >> m >> k;
    vector<P> lr(m);
    rep(i,m){
        cin >> lr[i].first >> lr[i].second;
    }
    vector<ll> a_prev(n+2,1);
    a_prev[0] = 0;
    vector<ll> a(n+2,0);
    rep(i,k){
        rep(j,m){
            int l = lr[j].first;
            int r = lr[j].second;
            ll plus = a_prev[r] - a_prev[l-1];
            a[l] = (a[l] + plus)%MOD;
            a[r+1] = (a[r+1] - plus + MOD)%MOD;
        }
        rep(c,2){
            for(int j=1;j<n+2;j++) a[j] = (a[j] + a[j-1])%MOD;
        }
        swap(a,a_prev);
        vector<ll> empty(n+2,0);
        swap(empty,a);
    }
    cout << (a_prev[n] - a_prev[n-1] + MOD)%MOD << endl;
    return 0;
}