//叫んで 藻掻もがいて 瞼まぶたを腫らしても
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll
typedef long double ld;
typedef pair<int , int> pii;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 110;
const int maxk = 1010;
const ll mod = 1e9+7;
#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}
int n , m , k;
int b[maxn][maxk] , s[maxn][maxk];
vector < pii > adj[maxn];
int dist[maxn][maxn] , mx[maxn][maxn];
ll w[maxn][maxn];
ll f[maxn][maxn];
ll d[maxn];
bool chk(ll x){
for(int i = 1 ; i <= n ; i ++)
for(int j = 1 ; j <= n ; j ++)if(dist[i][j] != dist[0][0])
w[i][j] = -(mx[i][j] - dist[i][j] * x);
else
w[i][j] = 1e15;
ms(d , 63);
d[1] = 0;
if(0){
for(int i = 1 ; i <= n ; i ++ , cout << endl)
for(int j = 1 ; j <= n ; j ++)
cout << w[i][j] << ' ' ;
}
for(int i = 1 ; i < n ; i ++)
for(int j = 1 ; j <= n ; j ++)
for(int k = 1 ; k <= n ; k ++)
if(d[j] < 1e18 - w[j][k])
d[k] = min(d[k] , d[j] + w[j][k]);
for(int j = 1 ; j <= n ; j ++)
for(int k = 1 ; k <= n ; k ++)if(k ^ j)
if(d[j] < 1e18 - w[j][k] and d[k] > d[j] + w[j][k])
return 1;
ms(f , 63);
for(int i = 1 ; i <= n ; i ++)f[i][i] = 0;
for(int i = 1 ; i <= n ; i ++)
for(int j = 1 ; j <= n ; j ++)
f[i][j] = min(f[i][j] , w[i][j]);
for(int k = 1 ; k <= n ; k ++)
for(int i = 1 ; i <= n ; i ++)
for(int j = 1 ; j <= n ; j ++)
if(f[i][k] != f[0][0] and f[k][j] != f[0][0])
f[i][j] = min(f[i][j] , f[i][k] + f[k][j]);
for(int i = 1 ; i <= n ; i ++)
for(int j = i+1 ; j <= n; j ++)
if(f[i][j] + f[j][i] == 0)
return 1;
return 0;
}
int32_t main(){
ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
cin >> n >> m >> k;
for(int i = 1 ; i <= n ; i ++)
for(int j = 1 ; j <= k ; j ++)
cin >> b[i][j] >> s[i][j];
ms(dist , 63);
for(int i = 1 ; i <= n ; i ++) dist[i][i] = 0;
for(int i = 1 ; i <= m ; i ++){
int u, v, w;
cin >> u >> v >> w;
adj[u].pb({v , w});
dist[u][v] = min(dist[u][v] , w);
}
for(int k = 1 ; k <= n ; k ++)
for(int i = 1 ; i <= n ; i ++)
for(int j = 1 ; j <= n ; j ++)
if(dist[i][k] != dist[0][0] and dist[k][j] != dist[0][0])
dist[i][j] = min(dist[i][j] , dist[i][k] + dist[k][j]);
for(int i = 1 ; i <= n ; i ++)
for(int j = 1 ; j <= n ; j ++) if(j ^ i)
for(int l = 1 ; l <= k ; l ++) if(s[j][l] != -1 and b[i][l] != -1)
mx[i][j] = max(mx[i][j] , s[j][l] - b[i][l]);
ll l = 0 , r = 1e10;
while(r - l > 1){
ll mid = (l + r) / 2;
if(chk(mid))l = mid;
else r = mid;
}
cout << l;
return(0);
}
