#include "bits/stdc++.h"
using namespace std;
struct edge {
int to, cap, rev;
};
bool used[101010];
vector<edge> g[101010];
static const int INF = 0x3f3f3f3f;
void add_edge(int from, int to, int cap) {
g[from].push_back((edge) { to, cap, (int)g[to].size() });
g[to].push_back((edge) { from, 0, (int)g[from].size() - 1 });
}
int dfs(int v, int t, int f) {
if (v == t) return f;
used[v] = true;
for (int i = 0; i < g[v].size(); i ++) {
edge& e = g[v][i];
if (!used[e.to] && e.cap > 0) {
int d = dfs(e.to, t, min(f, e.cap));
if (d > 0) {
e.cap -= d;
g[e.to][e.rev].cap += d;
return d;
}
}
}
return 0;
}
int MaxFlow(int s, int t) {
int flow = 0;
while (true) {
memset(used, false, sizeof(used));
int f = dfs(s, t, INF);
if (f == 0) return flow;
flow += f;
}
}
int main() {
int n, m, p, g;
cin >> n >> m >> p >> g;
int s = m, t = 0;
for (int i = 0; i < g; i ++) {
int l;
cin >> l;
add_edge(s, l, INF);
}
for (int i = 0; i < n; i ++) {
int a, b, c;
cin >> a >> b >> c;
add_edge(a, b, c);
}
int ans = MaxFlow(s, t);
if (ans < p) cout << "No" << endl;
else cout << "Yes" << endl;
return 0;
}