#include<iostream>
#include<vector>
using namespace std;
typedef long long ll;
const ll mod = 1e9 + 7;
#define inRange(x,a,b) (a <= x && x < b)

class STlazy{
private:
    int n;
    vector<ll> node, lazy;

public:
    STlazy(int siz){
        n = 1;
        while(n < siz)  n *= 2;
        node.resize(2*n-1, 0);
        lazy.resize(2*n-1, 0);
    }

    void eval(int k, int l, int r){
        if(lazy[k] == 0)    return;
        node[k] += lazy[k];
        node[k] %= mod;
        if(r-l > 1){
            lazy[2*k+1] += lazy[k]/2;
            lazy[2*k+2] += lazy[k]/2;
        }
        lazy[k] = 0;
    }

    void add(int a, int b, ll x, int k=0, int l=0, int r=-1){
        if(r < 0)   r = n;
        eval(k, l, r);
        if(r <= a || b <= l)    return;
        if(a <= l && r <= b){
            lazy[k] += (r-l)*x;
            lazy[k] %= mod;
            eval(k, l, r);
            return;
        }
        add(a, b, x, 2*k+1, l, (l+r)/2);
        add(a, b, x, 2*k+2, (l+r)/2, r);
        node[k] = (node[2*k+1] + node[2*k+2])%mod; 
    }

    ll query(int a, int b, int k=0, int l=0, int r=-1){
        if(r < 0)   r = n;
        if(r <= a || b <= l)    return 0;
        eval(k, l, r); 
        if(a <= l && r <= b)    return node[k];
        ll lx = query(a, b, 2*k+1, l, (l+r)/2);
        ll rx = query(a, b, 2*k+2, (l+r)/2, r);
        return (lx+rx)%mod;
    }
};

// 重複を除去しきれていない
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]--, r[i]--;
    STlazy st(n);
    st.add(0, 1, 1);
    for(int i = 0; i < k; i++){
        STlazy next(n);
        for(int j = 0; j < m; j++){
            next.add(l[j], r[j]+1, st.query(l[j], r[j]+1));
        }
        st = next;
    }
    cout << st.query(n-1, n) << endl;
    return 0;
}