n,m,k = map(int, input().split()) d = dict() num = dict() for i in range(n-1): a,b = map(int, input().split()) num[a,b] = i+1 d[a,b] = 0 for i in range(m): lis = list(map(int, input().split())) if d[lis[1],lis[2]] in d: d[lis[1],lis[2]] += 1 elif d[lis[2],lis[1]] in d: d[lis[1],lis[2]] += 1 ans = [] for i in d: if d[i] >= k: ans.append(num[i]) print(len(ans)) print(*ans)