import bisect

def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    N = int(data[idx])
    idx +=1
    M = int(data[idx])
    idx +=1
    X = int(data[idx])
    idx +=1
    
    C = list(map(int, data[idx:idx+N]))
    idx +=N
    
    from collections import defaultdict
    groups = defaultdict(int)
    for _ in range(M):
        A_j = int(data[idx])
        idx +=1
        B_j = int(data[idx])
        idx +=1
        Y_j = int(data[idx])
        idx +=1
        groups[(A_j, B_j)] += Y_j
    
    # Precompute positions for each color (1-based)
    color_pos = defaultdict(list)
    for i in range(N):
        color = C[i]
        color_pos[color].append(i+1)  # 1-based
    
    sum_Y = [0]*(N+1)
    
    for (a, b), total in groups.items():
        if a > N:
            continue
        if b not in color_pos:
            continue
        pos_list = color_pos[b]
        # Find first index >= a
        idx_p = bisect.bisect_left(pos_list, a)
        for p in pos_list[idx_p:]:
            K = p - a
            if K <= N:
                sum_Y[K] += total
    
    max_score = 0
    for K in range(N+1):
        current = X * K + sum_Y[K]
        if current > max_score:
            max_score = current
    print(max_score)

if __name__ == "__main__":
    main()