#include <bits/stdc++.h>

using i64 = long long;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int n, m, q;
    std::cin >> n >> m >> q;
    
    std::vector<int> w(n);
    for (int i = 0; i < n; i++) {
        std::cin >> w[i];
        w[i]--;
    }
    
    std::vector<std::vector<int>> adj(n);
    for (int i = 0; i < m; i++) {
        int u, v;
        std::cin >> u >> v;
        u--, v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    
    std::vector dis(100, std::vector<int>(n, -1));
    for (int t = 0; t < 100; t++) {
        std::queue<int> q;
        for (int i = 0; i < n; i++) {
            if (w[i] <= t) {
                q.push(i);
                dis[t][i] = 0;
            }
        }
        while (!q.empty()) {
            int x = q.front();
            q.pop();
            
            for (auto y : adj[x]) {
                if (dis[t][y] == -1) {
                    q.push(y);
                    dis[t][y] = dis[t][x] + 1;
                }
            }
        }
    }
    
    while (q--) {
        int p, a;
        std::cin >> p >> a;
        p--, a--;
        std::cout << dis[a][p] << "\n";
    }
    
    return 0;
}