from collections import deque
import sys
input = sys.stdin.readline

def solve() :
    N, K = map(int, input().split())
    build_time = [0] + list(map(int, input().split()))
    
    graph = [[] for _ in range(N+1)]
    indegree = [0]*(N+1)
    for _ in range(K) :
        x, y = map(int, input().split())
        graph[x].append(y)
        indegree[y] += 1
    
    qu = deque()
    dp = [0]*(N+1)
    
    for i in range(1, N+1) :
        if indegree[i] == 0 :
            qu.append(i)
            dp[i] = build_time[i]
    
    W = int(input())
    
    while qu :
        now = qu.popleft()
        
        if now == W :
            break
        
        for nxt in graph[now] :
            dp[nxt] = max(dp[nxt], dp[now] + build_time[nxt])
            
            indegree[nxt] -= 1
            if indegree[nxt] == 0 :
                qu.append(nxt)
                
    return dp[W]

ans = []

for _ in range(int(input())) :
    ans.append(solve())

print("\n".join(map(str, ans)))