#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<string>
#include<algorithm>
#include<ctime>
#include<cmath>
#include<queue>
using namespace std;
#define FILE "snackstore"
#define pii pair<long long,long long>
#define LL long long 
#define up(i,j,n) for(int i=j;i<=n;i++)
#define down(i,n,j) for(int i=n;i>=j;i--)
#define max(x,y) ((x)>(y)?(x):(y))
#define min(x,y) ((x)<(y)?(x):(y))
#define abs(x) ((x)<0?(-(x)):(x))
template<typename T>inline bool chkmax(T &a,T b){return a<b?a=b,true : false;}
template<typename T>inline bool chkmin(T &a,T b){return a>b?a=b,true : false;}
int read(){
	int x=0;char ch=getchar();bool flag=0;
	while(ch<'0'||ch>'9'){if(ch=='-')flag=1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return flag?-x:x;
}
namespace OI{
	const int maxn=110;
	const LL inf=100000000000000LL;
	int n,m,Q;
	struct node{
		int y,next,v;
	}e[50000];
	struct Node{
		int s,c,d,id;
	}a[1010000];
	bool cmcmp(){
		
	}
	int linkk[maxn],len=0;
	void insert(int x,int y,int v){
		e[++len].y=y;
		e[len].v=v;
		e[len].next=linkk[x];
		linkk[x]=len;
	}
	pii v[maxn];
	bool vis[maxn];
	priority_queue<pii,vector<pii >,greater<pii > > q;
	LL f[maxn][maxn][maxn];
	void dij(int s,int j){
		while(!q.empty())q.pop();
		memset(f[s][j],10,sizeof(f[s][j]));
		f[s][j][s]=0;
		q.push(make_pair(0,s));
		int now;
		while(!q.empty()){
			now=q.top().second;q.pop();
			if(vis[now]&&now!=s)continue;
			for(int i=linkk[now];i;i=e[i].next){
				if(e[i].v+f[s][j][now]<f[s][j][e[i].y]){
					f[s][j][e[i].y]=e[i].v+f[s][j][now];
					q.push(make_pair(f[s][j][e[i].y],e[i].y));
				}
			}
		}
	}
	bool p[maxn];
	int find(int c){
		int left=0,right=n+1,mid,ans;
		while(left<=right){
			mid=(left+right)>>1;
			if(v[mid].first<=c)left=mid+1;
			else ans=mid,right=mid-1;
		}
		return ans;
	}
	int g[maxn][maxn];
	void init(){
		n=read(),m=read(),Q=read();
		up(i,1,n)v[i].first=read(),v[i].second=i;
		int x,y,vv;
		up(i,1,m){x=read(),y=read(),vv=read();insert(x,y,vv);insert(y,x,vv);}
		sort(v+1,v+n+1);
		v[n+1].first=inf+1;
		up(i,1,Q)a[i].s=read(),a[i].c=read(),a[i].d=read(),p[a[i].s]=1,g[a[i].s][find(a[i].c)]=1;
		for(int s=1;s<=n;s++){//以s为起点
			memset(vis,0,sizeof(vis));
			for(int j=n+1;j>=0;j--){//枚举能到的点,j不可经过
				vis[v[j].second]=1;
				if(!g[s][j])continue;
				dij(s,j);
				sort(f[s][j]+1,f[s][j]+n+1);
			}
		}
	}
	int Find(int s,int pos,int d){
		int left=1,right=n,mid,ans=0;
		while(left<=right){
			mid=(left+right)>>1;
			if(f[s][pos][mid]>d)right=mid-1;
			else left=mid+1,ans=mid;
		}
		return ans;
	}
	void slove(){
		init();
		int s,c,d,pos;
		up(i,1,Q){
			pos=find(a[i].c);
			printf("%d\n",Find(a[i].s,pos,a[i].d)-1);
		}
	}
}
int main(){
	freopen(FILE".in","r",stdin);
	freopen(FILE".out","w",stdout);
	using namespace OI;
	slove();
	return 0;
}