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

#define all(x) (x).begin(),(x).end()
#define SP <<" "<<
#define MOD 1000000007
#define IINF 1000000000
#define LINF 1000000000000000000

typedef long long LL;
typedef long double LD;

LL inv(LL x){
  int n=MOD-2;
  LL ans=1;
  while(n){
    if(n&1) ans=(ans*x)%MOD;
    n/=2;
    x=x*x%MOD;
  }
  return ans;
}

LL inv2;

struct LazySegmentTree {
private:
  int n;
  vector<LL> node, lazy;

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

  void init(){
    for(int i=0;i<2*n-1;i++){
      node[i]=lazy[i]=0;
    }
  }

  void eval(int k, int l, int r) {
    if(lazy[k] != 0) {
      node[k] = (node[k]+lazy[k])%MOD;
      if(r - l > 1) {
          lazy[2*k+1] = (lazy[2*k+1]+lazy[k] *inv2)%MOD;
          lazy[2*k+2] = (lazy[2*k+2]+lazy[k] *inv2)%MOD;
      }
      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(b <= l || r <= a) return;
    if(a <= l && r <= b) {
      lazy[k] = (lazy[k]+(r - l) * x%MOD)%MOD;
      eval(k, l, r);
    }else {
      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 getsum(int a, int b, int k=0, int l=0, int r=-1) {
    if(r < 0) r = n;
    if(b <= l || r <= a) return 0;
    eval(k, l, r);
    if(a <= l && r <= b) return node[k];
    LL vl = getsum(a, b, 2*k+1, l, (l+r)/2);
    LL vr = getsum(a, b, 2*k+2, (l+r)/2, r);
    return (vl + vr)%MOD;
  }
};

int main(){
  int n,m,k;
  cin >> n >> m >> k;
  inv2=inv(2);
  vector<pair<int,int>> p(m);
  for(int i=0;i<m;i++){
    cin >> p[i].first >> p[i].second;
    p[i].first--;
  }

  LazySegmentTree seg(n);
  seg.add(0,1,1);
  vector<LL> sum(n);
  for(int i=0;i<k;i++){
    for(int j=0;j<m;j++){
      sum[j]=seg.getsum(p[j].first,p[j].second);
      // cout << sum[j] << " ";
    }
    // cout << endl;
    seg.init();
    for(int j=0;j<m;j++){
      seg.add(p[j].first,p[j].second,sum[j]);
    }
  }
  cout << seg.getsum(n-1,n) << endl;
  return 0;
}