import sys
from collections import defaultdict

def main():
    N, M, X = map(int, sys.stdin.readline().split())
    C = list(map(int, sys.stdin.readline().split()))
    
    sum_y = defaultdict(dict)
    for _ in range(M):
        A, B, Y = map(int, sys.stdin.readline().split())
        if B not in sum_y[A]:
            sum_y[A][B] = 0
        sum_y[A][B] += Y
    
    # Build color_to_a
    color_to_a = defaultdict(list)
    for a in sum_y:
        for c in sum_y[a]:
            if sum_y[a][c] > 0:
                color_to_a[c].append(a)
    
    delta = [0] * (N + 2)  # k can be 0 to N
    
    for i in range(1, N + 1):
        c = C[i - 1]
        if c not in color_to_a:
            continue
        for a in color_to_a[c]:
            if a > i:
                continue
            k = i - a
            if k < 0:
                continue
            # 避免重复访问sum_y，直接计算
            delta[k] += sum_y[a][c]
    
    max_score = 0
    for k in range(N + 1):
        score = k * X + delta[k]
        if score > max_score:
            max_score = score
    print(max_score)

if __name__ == '__main__':
    main()