from heapq import *

N,M,K=map(int,input().split())
A=list(map(int,input().split()))

G=[set() for i in range(N)]
for i in range(M):
    u,v=map(int,input().split())
    G[u-1].add(v-1)
    G[v-1].add(u-1)

mi=10**10
argmin=0
for i in range(N):
    if A[i]<mi:
        argmin=i
        mi=A[i]
        
dist=[False]*N
que=[]
for nv in G[argmin]:
    heappush(que,(A[nv],nv))
    
dist[argmin]=True
now=mi
while (len(que)):
    val,v=heappop(que)
    if dist[v]:
        continue
    dist[v]=True

    if val-now>K:
        print('No')
        break
    
    now=val
    for nv in G[v]:
        if dist[nv]:
            continue
        heappush(que,(A[nv],nv))
else:
    print('Yes')