// 人外有人，天外有天
// author: Ausp3x
#pragma GCC optimize("O3, fast-math")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#define fi first
#define se second
#define pb push_back
// #define DEBUG
typedef long long lng;
typedef __int128 lll;
template<class T>
using indexed_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T> // lower_bound and upper_bound are broken
using indexed_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
int const INF32 = 0x3f3f3f3f;
lng const INF64 = 0x3f3f3f3f3f3f3f3f;
struct FloydWarshall {
int n;
vector<vector<lng>> dis;
FloydWarshall(int n, vector<vector<lng>> dis) : n(n), dis(dis) {
assert(this->dis.size() == this->n + 1);
for (int i = 0; i <= this->n; i++) {
assert(this->dis[i].size() == this->n + 1);
}
}
void runFloydWarshall(int bgn, int end) {
assert(0 <= bgn && bgn <= n);
assert(0 <= end && end <= n);
for (int k = bgn; k <= end; k++) {
for (int i = bgn; i <= end; i++) {
for (int j = bgn; j <= end; j++) {
dis[i][j] = min(dis[i][j], dis[i][k] + dis[k][j]);
}
}
}
return;
}
};
void solve() {
int n, m, x;
cin >> n >> m >> x;
vector<vector<lng>> B(n + 1, vector<lng>(x + 1)), S(n + 1, vector<lng>(x + 1));
for (int i = 1; i <= n; i++)
for (int j = 1; j <= x; j++)
cin >> B[i][j] >> S[i][j];
vector<vector<lng>> adjm(n + 1, vector<lng>(n + 1, INF64));
for (int i = 0; i < m; i++) {
int u, v, w;
cin >> u >> v >> w;
adjm[u][v] = w;
}
FloydWarshall fw1(n, adjm);
fw1.runFloydWarshall(1, n);
vector<vector<lng>> profit(n + 1, vector<lng>(n + 1));
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
for (int k = 1; k <= x; k++)
if (B[i][k] != -1 && S[j][k] != -1)
profit[i][j] = max(profit[i][j], S[j][k] - B[i][k]);
lng l = 0, r = 1'000'000'001;
while (r - l > 1) {
lng md = (l + r) / 2;
vector<vector<lng>> adjm2(n + 1, vector<lng>(n + 1, INF64));
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
adjm2[i][j] = md * min(fw1.dis[i][j], INF64 / md) - profit[i][j];
FloydWarshall fw2(n, adjm2);
fw2.runFloydWarshall(1, n);
bool has_nonnegative_cycle = false;
for (int i = 1; i <= n; i++)
if (fw2.dis[i][i] <= 0)
has_nonnegative_cycle = true;
if (has_nonnegative_cycle)
l = md;
else
r = md;
}
cout << l << endl;
return;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
