#include <bits/stdc++.h>
#define ft first
#define sc second
#define lb lower_bound
#define ub upper_bound
#define pb(t) push_back(t)
#define pt(num) cout << num << "\n"
#define chmax(a, b) (a<b ? a=b : 0)
#define chmin(a, b) (a>b ? a=b : 0)
#define max(a, b) ((a)>(b) ? (a):(b))
#define min(a, b) ((a)<(b) ? (a):(b))
#define moC(a, s, b) (a)=((a)s(b)+MOD)%MOD
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
typedef map<ll, ll> Map;
static const ll INF=1e18;
static const ll MAX=1e5+7;
static const ll MOD=1e9+7;



ll dp[3333][3333]={};

int main(void) {
    ll N, M, K;
    cin >> N >> M >> K;
    ll l[3333], r[3333];
    ll i, j;
    
    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]);
    
    
}