#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=105;
const int M=205;
const int K=1005;
const ll inf=1e18;
int n,k,m;
ll b[N][K],s[N][K];
ll dist[N][N],prof[N][N],dp[N][N];
void foyld(ll (&d)[N][N]){
for(int k=1;k<=n;k++)for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
}
bool check(ll cost){
for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)dp[i][j]=dist[i][j]<inf?dist[i][j]*cost-prof[i][j]:inf;
foyld(dp);
for(int i=1;i<=n;i++)if(dp[i][i]<=0)return true;
return false;
}
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
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];
for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)dist[i][j]=inf;
for(int i=1;i<=m;i++){
int u,v,w;
cin >> u >> v >> w;
dist[u][v]=w;
}
foyld(dist);
for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)for(int k=1;k<=::k;k++)if(b[i][k]>0&&s[j][k]>0)
prof[i][j]=max(prof[i][j],s[j][k]-b[i][k]);
ll l=0,r=1e9;
while(l<r){
ll m=(l+r+1)/2;
if(check(m))l=m;
else r=m-1;
}
cout << l << "\n";
}
