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

const long long N = 1e5 + 7, inf = 1e17;

struct e {
    long long c;
    int v;
};

vector <e> g[N], q, Q;

int n, m, s = -1, f = -1, u[N], w, U[N];

vector <long long> d(N, inf), D(N, inf), a(N, 0);

void dfs(int v, int x) {
    if (g[v].size() != 2) {
        if (s == -1)
            s = v;
        else
            if (f == -1)
                f = v;
        u[v] = -1;
        return;
    }
    u[v] = x;
    for (auto i : g[v])
        if (!u[i.v])
            dfs(i.v, x);
}

void F (int pv, int v, int e) {
    U[v] = 1;
    a[v] = a[pv] + e;
    for (auto i : g[v])
        if (!U[i.v])
            F(v, i.v, i.c);
}

main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    freopen("input.txt", "r", stdin);

    cin >> n >> m >> w;
    for (int i = 0; i < m; ++i) {
        int x, y, c;
        cin >> x >> y >> c;
        g[--x].push_back({c, --y});
        g[y].push_back({c, x});
    }
    for (int i = 0; i < n; ++i)
        if (!u[i])
            dfs(i, i + 1);
    U[s] = U[f] = 1;
    for (auto i : g[s])
        if (!U[i.v])
            F(s, i.v, i.c);
    d[s] = 0;
    q.push_back({0, s});
    D[f] = 0;
    Q.push_back({0, f});
    for (int i = 0; i < q.size(); ++i) {
        int u = q[i].v;
        for (auto j : g[u]) {
            int v = j.v;
            long long c = j.c;
            if (d[v] > c + d[u])
                d[v] = c + d[u],
                q.push_back({d[v], v});
        }
    }
    for (int i = 0; i < Q.size(); ++i) {
        int u = Q[i].v;
        for (auto j : g[u]) {
            int v = j.v;
            long long c = j.c;
            if (D[v] > c + D[u])
                D[v] = c + D[u],
                Q.push_back({D[v], v});
        }
    }
    for (int i = 0; i < w; ++i) {
        int x, y;
        cin >> x >> y;
        --x;
        --y;
        if (x == s && y == f || y == s && x == f) {
            cout << d[f] << ' ';
            continue;
        }
        cout << min(min({min(d[x], D[x]) + min(d[y], D[y]) + d[f], d[x] + d[y], D[x] + D[y]}), u[x] == u[y] ? abs(a[x] - a[y]) : inf) << ' ';
    }

    return 0;
}