## https://yukicoder.me/problems/no/1502

from collections import deque

MOD = 10 ** 9 + 7

def solve(N, M, K, next_nodes):
    if K == 0:
        return 0

    passed = [False] * N

    polyes = [None for _ in range(N)]
    ranges = [[1, K] for _ in range(N)]
    answer = 1
    for s_i in range(N):
        if not passed[s_i]:
            queue = deque()
            queue.append(s_i)
            polyes[s_i] = (1, 0) 

            array = []            
            while len(queue) > 0:
                v = queue.popleft()

                for w, z in next_nodes[v]:

                    if not passed[w]:
                        polyes[w] = (-1 * polyes[v][0], z - 1 * polyes[v][1])
                        passed[w] = True
                        array.append(w)
                        queue.append(w)
                    else:
                        if polyes[v][0] != polyes[w][0]:
                            if polyes[v][1] + polyes[w][1] == z:
                                continue
                            else:
                                return 0   
                        elif polyes[v][0] == polyes[w][0]:
                            X =  z - polyes[v][1] - polyes[w][1]
                            X *= polyes[v][0]
                            if X % 2 == 0:
                                x0 = X // 2
                                if ranges[s_i][0] <= x0 <= ranges[s_i][1]:
                                    ranges[s_i][0] = x0
                                    ranges[s_i][1] = x0
                                    continue
                                else:
                                    return 0
                            else:
                                return 0
        
            # 範囲を計算
            x_min, x_max = ranges[s_i]
            for w in array:
                if polyes[w][0] == 1:
                    x_min = max(x_min, ranges[w][0] -  polyes[w][1])
                    x_max = min(x_max, ranges[w][1] - polyes[w][1])
                else:
                    x_min =max(x_min, polyes[w][1] - ranges[w][1])
                    x_max = min(x_max, polyes[w][1] - ranges[w][0])
            
            if x_min <= x_max:
                answer *= (x_max - x_min + 1) % MOD
                answer %= MOD
            else:
                return 0
    return answer


def main():
    N, M, K = map(int, input().split())
    next_nodes = [[] for _ in range(N)]
    for _ in range(M):
        x, y, z = map(int, input().split())
        next_nodes[x - 1].append((y - 1, z))
        next_nodes[y - 1].append((x - 1, z))

    
    ans1 = solve(N, M, K, next_nodes)
    ans2 = solve(N, M, K - 1, next_nodes)

    answer = (ans1 - ans2) % MOD
    print(answer)






if __name__ == "__main__":
    main()