#include<bits/stdc++.h>
using namespace std;
#define PII pair<int,int>
const int N=5e4+10;
vector<PII>G[N];
int n,m,st,p,t,dis[N],vis[N];
void dij()
{
    priority_queue<PII,vector<PII>,greater<PII> >q;
    memset(dis,0x3f,sizeof(dis));dis[st]=0;
    memset(vis,0,sizeof(vis));
    q.push({0,st});
    while(!q.empty())
    {
        int x=q.top().second;q.pop();
        if(vis[x])continue;vis[x]=1;
        for(auto i:G[x])
        {
            int y=i.first,w=i.second;
            if(dis[y]>dis[x]+w)dis[y]=dis[x]+w,q.push({dis[y],y});
        }
    }
}
int main()
{
    int q;scanf("%d%d%d",&n,&m,&q);st=1;
    for(int i=1,x,y,w;i<=m;i++)scanf("%d%d%d",&x,&y,&w),G[x].push_back({y,w}),G[y].push_back({x,w});
    dij();
    while(q--)
    {
        int x,y;scanf("%d%d",&x,&y);
        printf("%d\n",dis[x]+dis[y]);
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define PII pair<int,int>
const int N=5e4+10;
vector<PII>G[N];
int n,m,st,p,t,dis[N],vis[N];
void dij()
{
    priority_queue<PII,vector<PII>,greater<PII> >q;
    memset(dis,0x3f,sizeof(dis));dis[st]=0;
    memset(vis,0,sizeof(vis));
    q.push({0,st});
    while(!q.empty())
    {
        int x=q.top().second;q.pop();
        if(vis[x])continue;vis[x]=1;
        for(auto i:G[x])
        {
            int y=i.first,w=i.second;
            if(dis[y]>dis[x]+w)dis[y]=dis[x]+w,q.push({dis[y],y});
        }
    }
}
int main()
{
    int q;scanf("%d%d%d",&n,&m,&q);st=1;
    for(int i=1,x,y,w;i<=m;i++)scanf("%d%d%d",&x,&y,&w),G[x].push_back({y,w}),G[y].push_back({x,w});
    dij();
    while(q--)
    {
        int x,y;scanf("%d%d",&x,&y);
        printf("%d\n",dis[x]+dis[y]);
    }
    return 0;
}