#include<bits/stdc++.h>
#pragma GCC optimize("trapv")
using namespace std;
const int mod=(int)1e9+7; 
#define endl '\n'
#define all(arr) arr.begin(),arr.end()
#define allr(arr) arr.rbegin(),arr.rend()
#define sz size()
#define int long long
int dis[101][101];
int buysell[101][101];
int dis1[101][101];
int buy[101][1001];
int sell[101][1001];
int inf=1e18;
bool overflow(int a,int b)
{
    if(a>=(inf/b))return 1;
    else return 0;
}
void iforgor()
{
    int n,m,k;
    cin>>n>>m>>k;
    for(int i=0;i<=n;i++)for(int j=0;j<k;j++)buysell[i][j]=-1e15;
    for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)dis[i][j]=1e18;
    for(int i=1;i<=n;i++)
    {
        for(int j=0;j<k;j++)
        {
            int a,b;
            cin>>a>>b;
            buy[i][j]=a;
            sell[i][j]=b;
        }
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++){
            for(int e=0;e<k;e++)
            {
                if(buy[i][e]==-1||sell[j][e]==-1)continue;
                buysell[i][j]=max(buysell[i][j],sell[j][e]-buy[i][e]);
            }
        }
    }
    for(int i=0;i<m;i++)
    {
        int a,b,c;
        cin>>a>>b>>c;
        dis[a][b]=c;
    }
    for(int kk=1;kk<=n;kk++)
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                dis[i][j]=min(dis[i][j],dis[i][kk]+dis[kk][j]);
    int ans=0;
    int l=1,r=2e9;
    int ez=0;
    while(l<=r)
    {
        int mid=(l+r)/2;
        bool negcyc=false;
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                dis1[i][j]=1e18; 
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++){
                if(overflow(mid,dis[i][j])||buysell[i][j]==1e18)dis1[i][j]=1e18;
                else
                dis1[i][j]=mid*dis[i][j]-buysell[i][j];
            }
        for(int kk=1;kk<=n;kk++)        
            for(int i=1;i<=n;i++)
                for(int j=1;j<=n;j++)
                    dis1[i][j]=min(dis1[i][j],dis1[i][kk]+dis1[kk][j]);
        for(int i=1;i<=n;i++)if(dis1[i][i]<=0)negcyc=true,ez=i;
        if(negcyc)
        {
            ans=mid;
            l=mid+1;
        }
        else r=mid-1;
    }
    cout<<ans<<endl;
}   
signed main()
{
    ios_base::sync_with_stdio(false);   
    cin.tie(NULL);   
    int t=1;
    // cin>>t;
    while(t--)iforgor();
}   

implementer.cpp: In function ‘void grader()’:
implementer.cpp:138:11: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  138 |     fscanf(fin, "%d %d %d",&F,&G,&maxQueries);
      |     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
implementer.cpp: In function ‘void runGame(int)’:
implementer.cpp:89:11: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   89 |     fscanf(fin,"%d %d",&N,&W);
      |     ~~~~~~^~~~~~~~~~~~~~~~~~~
implementer.cpp:91:15: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   91 |         fscanf(fin,"%d",&P[i]);
      |         ~~~~~~^~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccOVzPdj.o: in function `main':
answer.code:(.text.startup+0x0): multiple definition of `main'; /tmp/ccQl5Lkh.o:implementer.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccQl5Lkh.o: in function `runGame(int)':
implementer.cpp:(.text+0x127): undefined reference to `minValue(int, int)'
/usr/bin/ld: implementer.cpp:(.text+0x15d): undefined reference to `allValues(int, int, int*)'
/usr/bin/ld: implementer.cpp:(.text+0x1b7): undefined reference to `maxValue(int, int)'
/usr/bin/ld: implementer.cpp:(.text+0x1e7): undefined reference to `greaterValue(int, int)'
collect2: error: ld returned 1 exit status