#include <bits/stdc++.h>
using namespace std;

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int N, M;
    long long K;
    cin >> N >> M >> K;
    assert(2 <= N && N <= 200'000);
    assert(1 <= M && M <= 200'000);
    assert(1 <= K && K <= 1'000'000'000'000'000'000);
    vector<vector<pair<int, long long>>> E(N);
    for (int i = 0; i < M; i++) {
        int u, v;
        long long t;
        cin >> u >> v >> t;
        assert(1 <= min(u, v) && max(u, v) <= N);
        assert(1 <= t && t <= 1'000'000'000'000'000'000);
        u--; v--;
        E[u].emplace_back(v, t);
        E[v].emplace_back(u, t);
    }
    vector<long long> D(N, -1);
    D[0] = 0;
    queue<int> Q;
    Q.emplace(0);
    while (!Q.empty()) {
        int v = Q.front();
        Q.pop();
        for (auto [u, t] : E[v]) if (D[u] == -1) {
            D[u] = (D[v] + t) % K;
            Q.emplace(u);
        }
    }
    long long g = K;
    for (int i = 0; i < N; i++) {
        for (auto [j, t] : E[i]) {
            g = __gcd(g, D[i] - D[j] - t);
            if (g < 0) g = -g;
        }
    }
    cout << D[N - 1] % g << endl;
    return 0;
}