#include <bits/stdc++.h>
#define mp make_pair
#define all(vec) vec.begin(),vec.end()
using namespace std;
using ll=long long;
using P=pair<ll,ll>;
const ll INF=1LL<<30;
const ll LINF=1LL<<60;
const double eps=1e-9;
const ll MOD=1000000007LL;
template<typename T>void chmin(T &a,T b){a=min(a,b);};
template<typename T>void chmax(T &a,T b){a=max(a,b);};
template<typename T>vector<T> make_v(size_t a){return vector<T>(a);}
template<typename T,typename... Ts>auto make_v(size_t a,Ts... ts){return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));}
template<typename T,typename V>typename enable_if<is_class<T>::value==0>::type fill_v(T& t,const V& v){t=v;}
template<typename T,typename V>typename enable_if<is_class<T>::value!=0>::type fill_v(T& t,const V& v){for(auto &e:t)fill_v(e,v);};
int dx[4]={0,1,0,-1};
int dy[4]={1,0,-1,0};
template <typename T>
struct BinaryIndexedTree{
    vector<T> node;
    int n;
    BinaryIndexedTree(int n):n(n){
        node.assign(++n,0);
    }
    void add(int k,T x){
        for(++k;k<n;k+=k&-k){
            node[k]+=x;
            node[k]%=MOD;
        }
    }
    T sum(int k){
        T res=0;
        for(++k;k>0;k-=k&-k){
            res+=node[k];
            res%=MOD;
        }
        return res;
    }
};
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<BinaryIndexedTree<ll>> bit(k+10,BinaryIndexedTree<ll>(n+10));
    bit[0].add(1,1);
    vector<ll> sum(n+10);
    for(int i=1;i<=n;i++)sum[i]=1;
    for(int i=0;i<k;i++){
        for(int j=0;j<m;j++){
            ll s=(sum[r[j]]-sum[l[j]-1]+MOD)%MOD;
            bit[i+1].add(l[j],s);
            bit[i+1].add(r[j]+1,MOD-s);
        }
        sum[0]=0;
        for(int j=1;j<=n;j++){
            ll s=bit[i+1].sum(j);
            sum[j]=sum[j-1]+s;
            sum[j]%=MOD;
        }
    }
    ll ans=(sum[n]-sum[n-1]+MOD)%MOD;
    cout<<ans<<endl;
}