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

for _ in range(int(input())) :
    N, K = map(int, input().split())
    
    build_time = [0] + list(map(int, input().split()))
    
    build_info = [[] for _ in range(N+1)]
    for _ in range(K) :
        x, y = map(int, input().split())
        build_info[y].append(x)
        
    W = int(input())
    
    dp = [-1]*(N+1)
    
    def solve(target) :
        if dp[target] == -1 :
            max_build_time = 0
            for prev in build_info[target] :
                max_build_time = max(max_build_time, solve(prev))
        
            dp[target] = max_build_time + build_time[target]
        
        return dp[target]
    
    print(solve(W))