#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10;
const int maxm = 1e5 + 10;
const int inf = 1e9;
const int mod = 1e6 + 3;
int getint() {
  char c;
  while ((c = getchar()) && !(c >= '0' && c <= '9') && c != '-')
    ;
  int ret = c - '0', sgn = 0;
  if (c == '-') sgn = 1, ret = 0;
  while ((c = getchar()) && c >= '0' && c <= '9') ret = ret * 10 + c - '0';
  if (sgn) ret = -ret;
  return ret;
}
long long dp[1 << 20][20];
int g[20][20], a[20];
int n, m, k;
int get(int s) {
  int flag = 0;
  for (int i = 0; i < n; i++) {
    if (s & (1 << i)) flag++;
  }
  return flag;
}
int main() {
  while (scanf("%d%d%d", &n, &m, &k) == 3) {
    int i;
    for (i = 1; i <= n; i++) a[i - 1] = getint();
    memset(g, 0, sizeof(g));
    for (i = 1; i <= k; i++) {
      int u = getint();
      int v = getint();
      g[u - 1][v - 1] = getint();
    }
    for (int s = 0; s < (1 << n); s++) {
      for (int i = 0; i < n; i++) {
        dp[s][i] = -inf;
      }
    }
    for (i = 0; i <= n - 1; i++) dp[1 << i][i] = a[i];
    for (int s = 0; s < (1 << n); s++) {
      for (int i = 0; i < n; i++)
        if (s & (1 << i)) {
          for (int j = 0; j < n; j++)
            if (j != i && (s & (1 << j)) == 0) {
              int temp = s | (1 << j);
              dp[temp][j] = max(dp[temp][j], dp[s][i] + g[i][j] + a[j]);
            }
        }
    }
    long long ans = -1;
    for (int s = 0; s < (1 << n); s++) {
      if (get(s) == m) {
        for (int i = 0; i < n; i++)
          if (s & (1 << i)) {
            ans = max(ans, dp[s][i]);
          }
      }
    }
    cout << ans << endl;
  }
  return 0;
}
