#include <bits/stdc++.h>
#include <string>
#define ft first
#define sc second
#define pt(sth) cout << sth << "\n"
#define chmax(a, b) (a)=max(a, b);
#define chmin(a, b) (a)=min(a, b);
#define moC(a, s, b) (a)=((a)s(b)+MOD)%MOD
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
static const ll INF=1e18;
static const ll MAX=101010;
static const ll MOD=1e9+7;


/*
 for(i=0; i<N; i++)
   cin >> a[i];
*/

ll dp[3333][3333];

int main(void) {
  ll i, j, k;
  
  ll N, M, K;
  cin >> N >> M >> K;
  ll l[3333], r[3333];
  
  
  for(i=0; i<M; i++) cin >> l[i] >> r[i];
  
  dp[0][1]=1;
  for(i=0; i<K; i++) {
    ll s[3333]={};
    for(j=1; j<=N; j++) s[j]=(s[j-1]+dp[i][j])%MOD;
    
    for(j=0; j<M; j++) {
      ll t=s[r[j]]-s[l[j]-1];
      moC(dp[i+1][l[j]], +, t);
      moC(dp[i+1][r[j]+1], +, -t);
    }
    
    for(j=0; j<N; j++) moC(dp[i+1][j+1], +, dp[i+1][j]);
  }
  
  pt(dp[K][N]);
}