#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

#define fi first
#define se second
#define repl(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rep(i,n) repl(i,0,n)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl
#define mmax(x,y) (x>y?x:y)
#define mmin(x,y) (x<y?x:y)
#define maxch(x,y) x=mmax(x,y)
#define minch(x,y) x=mmin(x,y)
#define uni(x) x.erase(unique(all(x)),x.end())
#define exist(x,y) (find(all(x),y)!=x.end())
#define bcnt __builtin_popcountll

#define INF 1e16
#define mod 1000000007

ll dp[2][3001];

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll n,m,k;
  vector<P> rs;

  cin>>n>>m>>k;
  rep(i,m){
    ll a,b;
    cin>>a>>b;
    a--;
    rs.push_back(P(a,b));
  }

  dp[0][0]=1;

  ll crt=0,nxt=1;
  rep(i,k){
    vector<ll> sum(n+1,0);
    rep(j,n){
      sum[j+1]=(sum[j]+dp[crt][j])%mod;
      dp[nxt][j]=0;
    }

    rep(j,m){
      ll v=(sum[rs[j].se]-sum[rs[j].fi]+mod)%mod;
      (dp[nxt][rs[j].fi]+=v)%=mod;
      (dp[nxt][rs[j].se]+=mod-v)%=mod;
    }

    rep(j,n)(dp[nxt][j+1]+=dp[nxt][j])%=mod;

    swap(crt,nxt);
  }
  cout<<dp[crt][n-1]<<endl;

  return 0;
}