感觉对斯坦纳树还是有很多疑惑啊……
等到时候noip没有爆零的话再回来填坑好了
//minamoto
#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>
using namespace std;
#define getc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
char buf[<<],*p1=buf,*p2=buf;
template<class T>inline bool cmin(T&a,const T&b){return a>b?a=b,:;}
inline int read(){
#define num ch-'0'
char ch;bool flag=;int res;
while(!isdigit(ch=getc()))
(ch=='-')&&(flag=true);
for(res=num;isdigit(ch=getc());res=res*+num);
(flag)&&(res=-res);
#undef num
return res;
}
const int N=1e6+;
int head[N],Next[N],ver[N],edge[N],tot;
inline void add(int u,int v,int e){
ver[++tot]=v,Next[tot]=head[u],head[u]=tot,edge[tot]=e;
}
int col[N],id[N],f[][],g[];
int vis[N],sum[N],n,m,k;
queue<int> q;
void spfa(int now){
while(!q.empty()){
int u=q.front();q.pop(),vis[u]=;
for(int i=head[u];i;i=Next[i]){
int v=ver[i];
if(f[v][now]>f[u][now]+edge[i]){
f[v][now]=f[u][now]+edge[i];
if(!vis[v]) vis[v]=,q.push(v);
}
}
}
}
int tmp[];
bool check(int S){
memset(tmp,,sizeof(tmp));
for(int i=;i<=;++i)
if(S&(<<i-)) ++tmp[col[i]];
for(int i=;i<=;++i)
if(tmp[i]&&tmp[i]!=sum[i]) return ;
return ;
}
int main(){
// freopen("testdata.in","r",stdin);
n=read(),m=read(),k=read();
for(int i=;i<=m;++i){
int u=read(),v=read(),e=read();
add(u,v,e),add(v,u,e);
}
memset(f,0x3f,sizeof(f));
memset(g,0x3f,sizeof(g));
for(int i=;i<=k;++i)
col[i]=read(),id[i]=read(),++sum[col[i]],f[id[i]][<<i-]=;
int limit=(<<k)-;
for(int S=;S<=limit;++S){
for(int i=;i<=n;++i){
for(int SS=S;SS;SS=(SS-)&S)
cmin(f[i][S],f[i][SS]+f[i][S^SS]);
q.push(i),vis[i]=;
}
spfa(S);
}
for(int S=;S<=limit;++S)
for(int i=;i<=n;++i)
cmin(g[S],f[i][S]);
for(int S=;S<=limit;++S)
if(check(S))
for(int SS=S;SS;SS=(SS-)&S)
if(check(SS))
cmin(g[S],g[SS]+g[S^SS]);
printf("%d\n",g[limit]);
return ;
}