import sys
sys.setrecursionlimit(10**6)
input = sys.stdin.readline

ans = []

for _ in range(int(input())) :
    N, K = map(int, input().split())
    bt = [0] + list(map(int, input().split()))
    
    prev_build = [[] for _ in range(N+1)]
    for _ in range(K) :
        x, y = map(int, input().split())
        prev_build[y].append(x)
    
    W = int(input())
    dp = [-1]*(N+1)
    
    def build(n) :
        if dp[n] == -1 :
            prev_time = 0
            
            for prev in prev_build[n] :
                prev_time = max(prev_time, build(prev))
            
            dp[n] = prev_time + bt[n]
        
        return dp[n]
    
    ans.append(build(W))

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