#include <bits/stdc++.h>
#pragma GCC optimize(2)
using namespace std;
using ll = long long;

const int N = 1e5 + 5;
ll ar[N];
vector<int> g[N];
void add(int f, int t) {
    g[f].push_back(t);
    g[t].push_back(f);
}

void clr(int n) {
    n += 2;
    for (int i = 0; i <= n; ++i) {
        g[i].clear();
    }
}

int res[101][N];
queue<pair<int, int>> que[101];
void bfs(int x) {
    while (que[x].size()) {
        auto [u, d] = que[x].front();
        que[x].pop();
        for (auto &it : g[u]) {
            if (res[x][it] == 0x3f3f3f3f) {
                res[x][it] = d + 1;
                que[x].push({it, d + 1});
            }
        }
    }
}

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    memset(res, 0x3f, sizeof res);
    int n, m, q;
    cin >> n >> m >> q;
    for (int i = 1; i <= n; ++i) {
        cin >> ar[i];
    }
    for (int i = 1; i <= m; ++i) {
        int a, b;
        cin >> a >> b;
        add(a, b);
    }

    for (int i = 1; i <= n; ++i) {
        que[ar[i]].push({i, 0});
        res[ar[i]][i] = 0;
    }

    for (int i = 1; i <= 100; ++i) {
        bfs(i);
    }

    while (q--) {
        int u, c;
        cin >> u >> c;

        int ans = 0x3f3f3f3f;
        for (int i = 1; i <= c; ++i) {
            ans = min(ans, res[i][u]);
        }
        if (ans == 0x3f3f3f3f)
            ans = -1;
        cout << ans << '\n';
    }

    return 0;
}