#include<bits/stdc++.h>
using namespace std;
void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << h; if(sizeof...(t)) cerr << ", ";
DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL
#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;
void setIO(string NAME = "") {
cin.tie(0)->sync_with_stdio(0);
if(sz(NAME)) {
freopen((NAME + ".in").c_str(),"r",stdin);
freopen((NAME + ".out").c_str(),"w",stdout);
}
}
const ll INF = 1e18;
tcT> bool ckmin(T&a, const T&b) {
return b < a ? a = b, 1 : 0;
}
tcT> bool ckmax(T&a, const T&b) {
return b > a ? a = b, 1 : 0;
}
const int MX = 1e2+5;
int N, M, K;
ll B[MX][1005], S[MX][1005], E[MX][MX], d[MX][MX], chk[MX][MX];
bool ok(int tar) {
memset(chk, 0x3f, sizeof chk);
FOR(i,1,N+1) FOR(j,1,N+1) if(d[i][j] < INF) {
chk[i][j] = d[i][j]*tar - E[i][j];
}
FOR(k,1,N+1) FOR(i,1,N+1) FOR(j,1,N+1) ckmin(chk[i][j], chk[i][k] + chk[k][j]);
FOR(i,1,N+1) if(chk[i][i]<=0) return 1;
return 0;
}
void solve() {
memset(d, 0x3f, sizeof d);
memset(B, -1, sizeof B); memset(S, -1, sizeof S);
cin>>N>>M>>K;
FOR(i,1,N+1) {
FOR(j,1,K+1) cin>>B[i][j]>>S[i][j];
}
F0R(i,M) {
int u,v,c;
cin>>u>>v>>c;
ckmin(d[u][v], 1LL*c);
}
FOR(k,1,N+1) FOR(i,1,N+1) FOR(j,1,N+1) ckmin(d[i][j], d[i][k] + d[k][j]);
FOR(k,1,K+1) FOR(i,1,N+1) FOR(j,1,N+1) if(B[i][k] != -1 && S[j][k] != -1) ckmax(E[i][j], S[j][k] - B[i][k]);
int lo = 0, hi = 1e9;
while(lo<hi) {
int mid = lo + (hi-lo+1)/2;
if(ok(mid)) lo = mid;
else hi = mid-1;
}
cout << lo << nl;
}
int main() {
setIO();
int t=1;
//cin>>t;
while(t-->0) {
solve();
}
return 0;
}
