#include<bits/stdc++.h>
using namespace std;
#define  int long long
struct edge {
	int st, ed, wei;


} e[1200005];

int p[10025];
edge alle[1000005];
int rs[11];
bool cmp(edge a, edge b) {
	return a.wei < b.wei;
}
int find(int x) {
	if (x == p[x])return p[x];
	return p[x] = find(p[x]);

}


signed main() {
//	freopen("road2.in","r",stdin);
	int n, m, k;
	cin >> n >> m >> k;
	for (int i = 1; i <= n + k; i++) {
		p[i] = i;
	}
	for (int i = 1; i <= m; i++) {

		cin >> e[i].st >> e[i].ed >> e[i].wei;
	}

	sort(e + 1, e + m + 1, cmp);
	int po = 1;
	for (int i = 1; i <= k; i++) {

		cin >> rs[i];
		for (int ii = 1; ii <= n; ii++) {
			cin >> 	alle[po].wei ;
			alle[po].st = i + n;
			alle[po].ed = ii;
			po++;
		}

	}
	int total = 0;
	int counter = 0;
	for (int i = 1; i <= m; i++) {
		int a = find(e[i].st);
		int b = find(e[i].ed);
		if (a == b)continue;
		else {
			p[b] = a;

			total += e[i].wei;
			counter++;
			alle[po].st = e[i].st;
			alle[po].ed = e[i].ed;
			alle[po].wei = e[i].wei;
			po++;
			if (counter == n - 1) {
				break;
			}
		}

	}
	if (k == 0) {
		cout << total;
		return 0;
	}
	int us[11];
	int ttemp = 0, ma = total;
	sort(alle + 1, alle + po, cmp);
//	for (int i = 1; i <= po; i++) {
	//	cout << alle[i].st << " " << alle[i].ed << " " << alle[i].wei << endl;

//	}
	for (int i = 1; i < (1 << k); i++) {
		ttemp = 0;
		int tz = i;
		int cc = n, counter = 0;
		for(int j=1;j<=k;j++)us[j]=0;
		for (int j = 1; j <= k; j++) {
			if ((tz >> (j - 1)) & 1) {
				ttemp += rs[j];
				us[j] = 1;
				cc++;
			}
		}
	
		for (int ii = 1; ii <= n + k; ii++) {
			p[ii] = ii;
		}
		for (int zz = 1; zz < po; zz++) {
			if(alle[zz].st>n&&us[alle[zz].st-n] == 0){ continue;
			}
			//if(alle[zz].st>n&&us[alle[zz].st-n] == 1)	cout <<us[alle[zz].st-n];
			int a = find(alle[zz].st);
			int b = find(alle[zz].ed);
		//	cout << a << " " << b << " " << alle[zz].st << " " << alle[zz].ed <<" "<<ttemp<< endl;
			if (a == b)continue;
			else {
				p[b] = a;
				ttemp += alle[zz].wei;

				counter++;
				if (counter == cc - 1) {
				//	cout << total <<" "<< ttemp << endl;
					ma = min(ma, ttemp);
					break;
				}
			}

		}

	}
	cout << ma;
}