#include<stdio.h>
#include<iostream>
#include<stdlib.h>
#include<vector>
#include<string>
#include<set>
#include<map>
#include<queue>
#include<list>
#include<algorithm>
using namespace std;

#define ll long long

#define flow(from,to) (f[from][to] - f[to][from])
#define residue(from,to) (cap[from][to] - flow(from,to))

int cap[512][512];
int f[512][512];
typedef int V;


int d[512][512];
int dr[512][512];
int buf[512][512];

void wf( int N )
{
	for( int i = 0; i < N; i ++ )
	for( int j = 0; j < N; j ++ ){
		dr[i][j] = d[i][j];
	}
	for( int i = 0; i < N; i ++ ){
		dr[i][i] = 0;
	}


	for( int i = 0; i < N; i ++ )
	for( int j = 0; j < N; j ++ )
		buf[i][j] = dr[i][j];

	for( int k = 0; k < N; k ++ ){
		for( int i = 0; i < N; i ++ )
		for( int j = 0; j < N; j ++ ){
			if( dr[i][k] >= 0 && dr[k][j] >= 0 ){
				int dd = dr[i][k] + dr[k][j];
				if( dr[i][j] < 0 || dr[i][j] > dd )
					buf[i][j] = dd;
			}
		}

		for( int i = 0; i < N; i ++ )
		for( int j = 0; j < N; j ++ )
			dr[i][j] = buf[i][j];
	}
}

V mf( int s, int t, int n )
{
	int prev[512];
	for( int i = 0; i < n; i ++ )
		for( int j = 0; j < n; j ++ )
			f[i][j] = 0;
	V flow_sum = 0;
	while( 1 ){
		queue<int> q;
		for( int i = 0; i < n; i ++ )
			prev[i] = -1;
		prev[s] = -2;
		q.push( s );
		while( !q.empty() && prev[t] == -1 ){
			int pos = q.front();
			q.pop();
			for( int i = 0; i < n; ++ i ){
				if( prev[i] == -1 && residue(pos,i) > 0 ){
					prev[i] = pos;
					q.push( i );
				}
			}
		}
		if( prev[t] == -1 )
			return flow_sum;
		V r = -1;
		for( int i = t; prev[i] >= 0; i = prev[i] ){
			V res = residue(prev[i], i);
			if( r < 0 || res < r )
				r = res;
		}
//		printf( "%d %d\n", flow_sum, r );
		if( r > 0 ){
			for( int i = t; prev[i] >= 0; i = prev[i] ){
				f[prev[i]][i] += r;
			}
			flow_sum += r;
		}
	}
}

int main( void )
{
	FILE *in = fopen( "nucleus.in", "r" );

	while( 1 ){
		int N, M, L;
		fscanf( in, "%d%d%d", &N,&M, &L );
		if( feof( in ) )
			break;

		for( int i = 0; i < N; i ++ )
		for( int j = 0; j < N; j ++ )
			d[i][j] = L + 1;

//		d[i][0] = 0;

		for( int i = 0; i < M; i ++ ){
			int a, b, D;
			fscanf( in, "%d%d%d", &a, &b, &D );
			a -- , b --;
			d[a][b] = D;
			d[b][a] = D;
		}
		wf( N );
//		printf( "wf\n" );

		int n2 = N * 2 + 2;
		for( int i = 0; i < n2; i ++ )
		for( int j = 0; j < n2; j ++ )
			cap[i][j] = 0;
		for( int i = 0; i < N; i ++ )
		for( int j = 0; j < N; j ++ )
			if( dr[i][j] < L )
				cap[i + 2][j + 2 + N] = 100000000;

		for( int i = 0; i < N; i ++ ){
			int k;
			fscanf( in, "%d", &k );
			cap[0][2 + i] = k;
		}
		for( int i = 0; i < N; i ++ ){
			int k;
			fscanf( in, "%d", &k );
			cap[2 + N + i][1] = k;
		}
		printf( "%d\n", mf( 0, 1, n2 ) );
	}
	return 0;
}