// compile: make data
// run: time ./data < big.in > big.out && diff big.out big.ans
#include <bits/stdc++.h>
using namespace std;
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) _debug_print(#x, x);
#define Debug(x...) _debug_print_format(#x, x);
std::ifstream terminal("/dev/tty");
#define PP cerr<<"\033[1;30mpause...\e[0m",terminal.ignore();
#else
#define debug(x...)
#define Debug(x...)
#define PP
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
#define rep(i,a,b) for(int i=(a);i<(int)(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define FIND(a, x) ((find(a.begin(),a.end(),(x))!=a.end())?1:0)
#define cmin(x,...) x=min({(x),__VA_ARGS__})
#define cmax(x,...) x=max({(x),__VA_ARGS__})
#define INTMAX (int)(9223372036854775807)
#define INF (int)(1152921504606846976)
#define NaN (int)(0x8b88e1d0595d51d1)
#define double long double
#define int long long
#define uint unsigned long long
#define MAXN 200010

struct DSU {
    vector<int> parent, rank, s;
    DSU(int n) {
        parent.resize(n);
        rank.resize(n);
        s.resize(n, 1);
        rep(i, 0, n) parent[i] = i;
    }
    int find(int x) {
        if (parent[x] != x) parent[x] = find(parent[x]);
        return parent[x];
    }
    void unite(int x, int y) {
        int rx = find(x), ry = find(y);
        if (rx == ry) return;
        if (rank[rx] < rank[ry]) parent[rx] = ry, s[ry] = s[rx] + s[ry];
        else if (rank[rx] > rank[ry]) parent[ry] = rx, s[rx] = s[rx] + s[ry];
        else parent[ry] = rx, ++rank[rx], s[rx] = s[rx] + s[ry];
    }
    int get_size(int x) {
        return s[find(x)];
    }
};

struct Tree {
    int n;
    struct ed {
        int v, w;
    };
    vector<vector<ed>> e;
    struct node {
        vector<node*> ch;
        int wp;
        node *parent = nullptr;
        int depth;
    };
    vector<node> vertex;
    vector<int> removed;
    node *root;
    int H = 0;
    Tree(int V) {
        n = V;
        e.resize(n);
        vertex.resize(n);
        removed.resize(n);
    }
    void add_edge(int u, int v, int w) {
        e[u].push_back({v, w}), e[v].push_back({u, w});
    }
    int ind(node *x) {return x - &vertex[0]; }
    void setroot(int rt = 0) {
        if (root != &vertex[rt]) build(rt);
        root = &vertex[rt];
    }
    void build(int rt = 0) {
        function<void(int, int)> dfs = [&](int u, int pre) {
            node *x = &vertex[u];
            x->depth = !~pre ? 0 : vertex[pre].depth + 1;
            if (x->depth > H) H = x->depth;
            x->ch.clear();
            for (auto [v, w]: e[u]) {
                if (v == pre || removed[v]) continue;
                node *y = &vertex[v];
                x->ch.push_back(y);
                y->parent = x;
                y->wp = w;
                dfs(v, u);
            }
        };
        dfs(rt, -1);
    }
    vector<vector<int>> hp, maxw;
    vector<int> lg2;
    void getancestor() {
        lg2.resize(H+1);
        rep(i, 0, H+1) lg2[i] = log2(i);
        // hp.resize(n, vector<int>(lg2[H] + 1));
        hp.resize(lg2[H]+1, vector<int>(n));
        // maxw.resize(n, vector<int>(lg2[H] + 1, 0));
        maxw.resize(lg2[H]+1, vector<int>(n, 0));
        // rep(i, 0, n) hp[i][0] = vertex[i].parent ? ind(vertex[i].parent) : -1, maxw[i][0] = vertex[i].wp;
        rep(i, 0, n) hp[0][i] = vertex[i].parent ? ind(vertex[i].parent) : -1, maxw[0][i] = vertex[i].wp;
        rep(j, 1, lg2[H]+1) rep(i, 0, n) {
            // if (~hp[i][j-1]) hp[i][j] = hp[hp[i][j-1]][j-1], maxw[i][j] = max(maxw[i][j-1], maxw[hp[i][j-1]][j-1]);
            if (~hp[j-1][i]) hp[j][i] = hp[j-1][hp[j-1][i]], maxw[j][i] = max(maxw[j-1][i], maxw[j-1][hp[j-1][i]]);
            // else hp[i][j] = -1, maxw[i][j] = 0;
            else hp[j][i] = -1, maxw[j][i] = 0;
        }
    }
    int lca(int u, int v) {
        if (hp.empty()) getancestor();
        if (vertex[u].depth < vertex[v].depth) swap(u, v);
        int res = 0;
        // for (int k = lg2[H]; k >= 0; --k) if (vertex[u].depth - (1<<k) >= vertex[v].depth) cmax(res, maxw[u][k]), u = hp[u][k];
        for (int k = lg2[H]; k >= 0; --k) if (vertex[u].depth - (1<<k) >= vertex[v].depth) {
            // debug(u, k, maxw[k][u])
            cmax(res, maxw[k][u]), u = hp[k][u];
        }
        if (u == v) return res;
        for (int k = lg2[H]; k >= 0; --k) {
            // if (hp[u][k] != hp[v][k]) {
            if (hp[k][u] != hp[k][v]) {
                // cmax(res, maxw[u][k]), cmax(res, maxw[v][k]);
                cmax(res, maxw[k][u]), cmax(res, maxw[k][v]);
                // u = hp[u][k], v = hp[v][k];
                u = hp[k][u], v = hp[k][v];
            }
        }
        cmax(res, maxw[0][u], maxw[0][v]);
        return res;
    }
};

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

    int n, m, q; cin >> n >> m >> q;
    struct edge {
        int u, v, w;
    };
    vector<edge> e;
    rep(i, 0, m) {
        int u, v; cin >> u >> v;
        e.push_back({u-1, v-1, i+1});
    }
    rep(i, 0, n-1) e.push_back({i, i+1, INF});
    sort(e.begin(), e.end(), [](edge a, edge b) {
        return a.w < b.w;
    });
    DSU dsu(n);
    Tree t(n);
    for (auto &ed: e) {
        if (dsu.find(ed.u) == dsu.find(ed.v)) continue;
        t.add_edge(ed.u, ed.v, ed.w);
        dsu.unite(ed.u, ed.v);
    }
    t.build(0);
    t.getancestor();
    while (q--) {
        int u, v; cin >> u >> v; --u, --v;
        int ans = t.lca(u, v);
        if (ans == INF) ans = -1;
        // else if (ans == -INF) ans = 0;
        printf("%lld\n", ans);
    }

    return 0;
}