#include<bits/stdc++.h>
#include<bits/extc++.h>
#define int long long
#define inf 0x3f3f3f3f3f3f3f3f
#define maxn 3234
#define eps 1e-7
#define mod 1000000007
#define Mod 998244353
#define f(i,a,b) for(int i=a;i<=b;i++)
#define r(i,a,b) for(int i=a;i>=b;i--) 
#define fx(i,a,b,x) for(int i=a;i<=b;i+=x)
#define rx(i,a,b,x) for(int i=a;i>=b;i-=x) 
using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;
int T;
int n,m,k,a[maxn],b[maxn],dp[maxn][maxn],x[maxn];
void solve(){
	scanf("%lld%lld%lld",&n,&m,&k);
	f(i,1,m)scanf("%lld%lld",&a[i],&b[i]);
	dp[0][1]=1;
	f(i,0,k-1){
		f(j,1,n)x[j]=(x[j-1]+dp[i][j])%mod;
		f(j,0,m){
			int tmp=(x[b[j]]-x[a[j]-1]+mod)%mod;
			dp[i+1][a[j]]+=tmp,dp[i+1][b[j]+1]-=tmp;
		}
		f(j,1,n)dp[i+1][j]=(dp[i+1][j]+dp[i+1][j-1])%mod;
	}
	printf("%lld\n",(dp[k][n]+mod)%mod);
}
signed main(){
	T=1;
//	scanf("%lld",&T);
	while(T--)solve();
	return 0;
}