#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef long long int int64;

const int mod=1000000007;

void run(void){
  int n,m,k;
  scanf("%d%d%d",&n,&m,&k);
  int *l=(int *)calloc(m,sizeof(int));
  int *r=(int *)calloc(m,sizeof(int));
  int i;
  for(i=0;i<m;i++) scanf("%d%d",l+i,r+i);
  int *now=(int *)calloc(n+2,sizeof(int));
  for(i=1;i<=n+1;i++) now[i]=1;
  int *next=(int *)calloc(n+2,sizeof(int));
  while(k--){
    memset(next,0,sizeof(int)*(n+2));
    for(i=0;i<m;i++){
      int v=(now[r[i]]-now[l[i]-1]+mod)%mod;
      next[l[i]]=(next[l[i]]+v)%mod;
      next[r[i]+1]=(next[r[i]+1]+mod-v)%mod;
    }
    for(int iter=0;iter<2;iter++){
      for(i=1;i<=n+1;i++) next[i]=(next[i]+next[i-1])%mod;
    }
    int *swap=now;
    now=next;
    next=swap;
  }
  printf("%d\n",(now[n]-now[n-1]+mod)%mod);
}

int main(void){
  run();
  return 0;
}