//Never stop trying
/*#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")*/
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
typedef long long ll;
#define int ll
typedef string str;
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
const int MOD = 1e9 + 7; //998244353
const ll INF = 5e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up
template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
ll random(ll a, ll b){
return a + rng() % (b - a + 1);
}
#ifndef LOCAL
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl;
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;
void IO() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
}
int N,M,K;
int B[101][1001],S[101][1001];
int g[101][101],p[101][101],g2[101][101];
void floyd_warshall(int adj[101][101]){
FOR(k,1,N+1) FOR(i,1,N+1) FOR(j,1,N+1)
ckmin(adj[i][j],adj[i][k]+adj[k][j]);
}
int32_t main() {
boost; IO();
cin>>N>>M>>K;
FOR(i,1,N+1) FOR(j,1,K+1){
cin>>B[i][j]>>S[i][j];
}
FOR(i,1,N+1) FOR(j,1,N+1){
g[i][j]=INF;
p[i][j]=0;
FOR(k,1,K+1) if(B[i][k]!=-1 && S[i][k]!=-1)
ckmax(p[i][j],S[j][k]-B[i][k]);
}
FOR(i,0,M){
int u,v,w; cin>>u>>v>>w;
g[u][v]=w;
}
floyd_warshall(g);
int l=1,r=INF;
int ans=0;
while(l<=r){
int R=(l+r)/2;
FOR(i,1,N+1) FOR(j,1,N+1) g2[i][j]=R*min(g[i][j],INF/R) - p[i][j];
floyd_warshall(g2);
bool found=0;
FOR(i,1,N+1) if(g2[i][i]<=0) found=true;
if(found) l=R+1,ans=R;
else r=R-1;
}
cout << ans << endl;
return 0;
}
/* Careful!!!
.Array bounds
.Infinite loops
.Uninitialized variables / empty containers
.Multisets are shit
Some insights:
.Binary search
.Graph representation
.Write brute force code
.Change your approach
*/
