#include <iostream>
#include <vector>
#include <queue>
#include <climits>
#include <cstring>
#include <sstream>

const long MOD = static_cast<long>(1e9 + 7);
const int MID = static_cast<int>(1e5 + 7);
const long LMAX = LLONG_MAX;
const long LMIN = LLONG_MIN;
const int IMAX = INT_MAX;
const int IMIN = INT_MIN;

// 增加数组的第一维大小以防止越界访问
std::vector<int> adj[MID + 1];
int arr[MID + 1];
int va[MID + 1][105];
bool visited[MID + 1];
int n;
int row[] = {1, -1, 0, 0};
int col[] = {0, 0, 1, -1};

class FastIO {
public:
    FastIO() {
        std::ios_base::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }

    template<typename T>
    void read(T &x) {
        std::cin >> x;
    }
} io;

void bfs(int o) {
    std::queue<std::pair<int, int>> queue;
    for (int i = 1; i <= n; i++) {
        if (arr[i] == o) {
            queue.emplace(i, 0);
            va[i][o] = 0;
            visited[i] = true;
        }
    }

    while (!queue.empty()) {
        auto [idx, cnt] = queue.front();
        queue.pop();
        for (auto &nei : adj[idx]) {
            if (!visited[nei]) {
                va[nei][o] = std::min(va[nei][o], cnt + 1);
                visited[nei] = true;
                queue.emplace(nei, cnt + 1);
            }
        }
    }
}

void solve() {
    int m, q;
    io.read(n);
    io.read(m);
    io.read(q);

    for (int i = 1; i <= n; i++) {
        adj[i].clear();
        io.read(arr[i]);
    }

    for (int i = 1; i <= m; i++) {
        int a, b;
        io.read(a);
        io.read(b);
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    for (int i = 1; i <= n; i++) {
        std::fill(va[i], va[i] + 105, IMAX);
    }

    for (int i = 1; i <= 100; i++) {
        std::memset(visited, 0, sizeof(bool) * (n + 1)); // 调整访问数组的清空方式
        bfs(i);
    }

    for (int i = 1; i <= q; i++) {
        int pi, ai;
        io.read(pi);
        io.read(ai);
        long ans = IMAX;
        for (int j = 0; j <= ai; j++) {
            ans = std::min(ans, static_cast<long>(va[pi][j]));
        }
        if (ans == IMAX) {
            std::cout << "-1\n";
        } else {
            std::cout << ans << "\n";
        }
    }
}

int main() {
    int T = 1;
    while (T--) {
        solve();
    }
    std::cout.flush();
    return 0;
}