#include<set>
#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<vector>
#include<cstdio>
#include<bitset>
#include<cstring>
#include<iostream>
#include<algorithm>
#define ll long long
#define ld long double
using namespace std;
const double eps=1e-10;
char *p1,*p2,buf[100000];
#define nc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++)
int read() {int x=0,flag=1; char c=nc();if(c=='-'){flag=-1,c=nc();} while(c<48) c=nc(); while(c>47) x=(((x<<2)+x)<<1)+(c^48),c=nc(); return flag*x;}
int f[110][110];
int head[110];
int next[200000];
int to[200000];
int a[200000];
int b[200000];
ld v[200000];
int vis[110];
int cnt[110];
queue<int>que;
int s[110][1010];
int t[110][1010];
int tot;
int n,m,q;
int x,y,z;
ld ans;
ld dis[110];
void add(int x,int y,int w,int z)
{next[++tot]=head[x];head[x]=tot;to[tot]=y;a[tot]=w;b[tot]=z;
}
bool SPFA(int S)
{dis[S]=0;que.push(S);vis[S]=1;while(!que.empty()){int now=que.front();que.pop();vis[now]=0;for(int i=head[now];i;i=next[i]){if(dis[to[i]]>dis[now]+v[i]){dis[to[i]]=dis[now]+v[i];cnt[to[i]]=cnt[now]+1;if(cnt[to[i]]>150){return true;}if(!vis[to[i]]){vis[to[i]]=1;que.push(to[i]);}}}}return false;
}
int main()
{n=read();m=read();q=read();for(int i=1;i<=n;i++){for(int j=1;j<=q;j++){s[i][j]=read();t[i][j]=read();}}memset(f,0x3f,sizeof(f));for(int i=1;i<=m;i++){x=read();y=read();z=read();f[x][y]=min(f[x][y],z);add(x,y,0,z);}for(int k=1;k<=n;k++){for(int i=1;i<=n;i++){for(int j=1;j<=n;j++){f[i][j]=min(f[i][j],f[i][k]+f[k][j]);}}}for(int i=1;i<=n;i++){for(int j=1;j<=n;j++){if(f[i][j]==0x3f)continue;int mx=-1;for(int k=1;k<=q;k++){int num;if(s[i][k]==-1||t[j][k]==-1||s[i][k]>=t[j][k])continue;else num=t[j][k]-s[i][k];mx=max(mx,num);}if(mx==-1)continue;add(i,j,mx,f[i][j]);}}ld l=0,r=1e12;ans=-1;while(r-l>=eps){ld mid=(l+r)/2;for(int i=1;i<=tot;i++){v[i]=mid*b[i]-a[i];}for(int i=1;i<=n;i++){dis[i]=0;vis[i]=cnt[i]=0;}int flag=0;for(int i=1;i<=n;i++){if(dis[i]==0){if(SPFA(i)){l=mid;ans=mid;flag=1;break;}}}if(!flag){r=mid;}}printf("%lld",ans==-1?0ll:(ll)(ans+eps));
}