#include <iostream>
using namespace std;
typedef long long ll;

int N,M,K;
int L[3010],R[3010];
ll dp[3010][3010] = {},imos[3010] = {},elv[3010] = {},inf = 1e9+7;
int main(){
    cin >> N >> M >> K;
    for(int i=1;i<=M;i++){
        cin >> L[i] >> R[i];
    }
    dp[0][1] = 1;
    for(int k=1;k<=K;k++){
        for(int i=1;i<=N;i++){
            (dp[k-1][i] += dp[k-1][i-1])%=inf;//累積和
        }
        //エレベーター内の移動の総数
        for(int i=1;i<=N;i++){
            imos[i] = 0;
        }
        for(int i=1;i<=M;i++){
            elv[i] = (dp[k-1][R[i]]-dp[k-1][L[i]-1]+inf)%inf;
            (imos[L[i]] += elv[i])%=inf;
            (imos[R[i]+1] += -elv[i]+inf)%=inf;
        }
        for(int i=1;i<=N;i++){
            (imos[i] += imos[i-1])%=inf;
            dp[k][i] = imos[i];
        }
    }
/*    for(int i=1;i<=K;i++){
        for(int j=1;j<=N;j++){
            cout << dp[i][j] << " ";
        }
        cout << endl;
    }
*/    cout << dp[K][N] << endl;
}