#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <forward_list>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T, typename V>
void ndarray(vector<T>& vec, const V& val, int len) { vec.assign(len, val); }
template <typename T, typename V, typename... Args> void ndarray(vector<T>& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); }
template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }
template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }
const std::vector<std::pair<int, int>> grid_dxs{{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }
template <class T1, class T2> T1 floor_div(T1 num, T2 den) { return (num > 0 ? num / den : -((-num + den - 1) / den)); }
template <class T1, class T2> std::pair<T1, T2> operator+(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first + r.first, l.second + r.second); }
template <class T1, class T2> std::pair<T1, T2> operator-(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first - r.first, l.second - r.second); }
template <class T> std::vector<T> sort_unique(std::vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <class T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }
template <class T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }
template <class IStream, class T> IStream &operator>>(IStream &is, std::vector<T> &vec) { for (auto &v : vec) is >> v; return is; }

template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec);
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr);
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const pair<T, U> &pa);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa);
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp);
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp);
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl);

template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; }
template <class... T> std::istream &operator>>(std::istream &is, std::tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa) { return os << '(' << pa.first << ',' << pa.second << ')'; }
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";
#define dbg(x) std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl
#define dbgif(cond, x) ((cond) ? std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl : std::cerr)
#else
#define dbg(x) ((void)0)
#define dbgif(cond, x) ((void)0)
#endif

struct Problem {
    int N1, N2, N3;
    vector<pint> edges;

    int s() const { return N1 + N2 + N3; }
    int t() const { return s() + 1; }

    pint get_v(int vid) const {
        if (vid < N1) return {0, vid};
        if (vid < N1 + N2) return {1, vid - N1};
        if (vid < N1 + N2 + N3) return {2, vid - N1 - N2};
        exit(1);
    }

    int convert_to(int did, int i) const {
        if (did == 0) return i;
        if (did == 1) return i + N1;
        if (did == 2) return i + N1 + N2;
        exit(1);
    }
};

Problem truncate(const Problem &p) {
    vector dels(3, vector<int>());
    dels.at(0).assign(p.N1, 0);
    dels.at(1).assign(p.N2, 0);
    dels.at(2).assign(p.N3, 0);

    for (const auto &[u, v] : p.edges) {
        const auto [du, iu] = p.get_v(u);
        const auto [dv, iv] = p.get_v(v);

        if (du == dv) {
            ++dels.at(du).at(min(iu, iv));
            --dels.at(du).at(max(iu, iv));
        }
    }
    for (auto &v : dels) { FOR(i, 1, v.size()) v.at(i) += v.at(i - 1); }
    vector<vector<int>> alives(3);
    REP(d, 3) {
        REP(i, dels.at(d).size()) {
            if (!dels.at(d).at(i)) alives.at(d).push_back(i);
        }
    }
    Problem ret;
    ret.N1 = alives.at(0).size();
    ret.N2 = alives.at(1).size();
    ret.N3 = alives.at(2).size();
    for (auto [u, v] : p.edges) {
        if (u > v) swap(u, v);
        const auto [du, iu] = p.get_v(u);
        const auto [dv, iv] = p.get_v(v);
        int ju = arglb(alives.at(du), iu);
        int jv = arglb(alives.at(dv), iv);

        if (du == dv and ju == jv) continue;

        ret.edges.emplace_back(ret.convert_to(du, ju), ret.convert_to(dv, jv));
    }
    ret.edges = sort_unique(ret.edges);
    return ret;
}

struct Rect {
    int xl, xr;
    int yl, yr;

    lint area() const {
        lint xw = max(0, xr - xl);
        lint yw = max(0, yr - yl);
        return xw * yw;
    }

    Rect bottom_left(int x, int y) { return Rect{xl, min(xr, x), yl, min(yr, y)}; }

    Rect top_right(int x, int y) { return Rect{max(xl, x), xr, max(yl, y), yr}; }

    template <class OStream> friend OStream &operator<<(OStream &os, const Rect &x) {
        return os << "(" << x.xl << "," << x.xr << "," << x.yl << "," << x.yr << ")";
    }
};

lint solve(const Problem &p) {
    vector<vector<int>> switch13(p.N3 + 1), switch23(p.N3 + 1);

    multiset<int> xubs, yubs;
    xubs.insert(p.N1 + 1);
    yubs.insert(p.N2 + 1);

    vector<pint> rectv12s;
    rectv12s.emplace_back(p.N1 + 1, p.N2 + 1);
    for (auto [u, v] : p.edges) {
        if (u > v) swap(u, v);
        const auto [du, iu] = p.get_v(u);
        const auto [dv, iv] = p.get_v(v);
        assert(du != dv);
        if (du == 0 and dv == 1) {
            rectv12s.emplace_back(iu + 1, iv + 1);
        } else if (du == 0 and dv == 2) {
            switch13.at(iv).push_back(iu + 1);
            xubs.insert(iu + 1);
        } else if (du == 1 and dv == 2) {
            switch23.at(iv).push_back(iu + 1);
            yubs.insert(iu + 1);
        } else {
            // exit(1);
        }
    }
    dbg(rectv12s);
    vector<Rect> rects;
    rects.push_back(Rect{0, p.N1 + 1, 0, p.N2 + 1});
    for (auto [x, y] : sort_unique(rectv12s)) {
        if (rects.empty()) continue;
        auto last = rects.back();
        rects.pop_back();
        while (rects.size() and rects.back().yl >= y) rects.pop_back();
        if (rects.size()) {
            rects.back() = rects.back().bottom_left(x, y);
            if (!rects.back().area()) rects.pop_back();
        }
        rects.push_back(last.bottom_left(x, y));
        if (!rects.back().area()) rects.pop_back();
        rects.push_back(last.top_right(x, y));
        if (!rects.back().area()) rects.pop_back();
    }
    vector<lint> area_sum{0};
    vector<int> xrs, yrs;
    for (auto r : rects) {
        auto tmp = area_sum.back() + r.area();
        area_sum.push_back(tmp);
        xrs.push_back(r.xr);
        yrs.push_back(r.yr);
    }
    dbg(make_tuple(rects));
    dbg(area_sum);

    auto calc_area_bottomleft = [&](int x, int y) -> lint {
        int i = min(arglb(xrs, x), arglb(yrs, y));
        lint ret = area_sum.at(i);
        if (i < int(rects.size())) ret += rects.at(i).bottom_left(x, y).area();
        return ret;
    };

    int xlb = 0, ylb = 0;
    lint ret = 0;
    REP(z, p.N3 + 1) {
        int xub = *xubs.cbegin();
        int yub = *yubs.cbegin();
        if (xlb < xub and ylb < yub) {
            ret += calc_area_bottomleft(xub, yub) + calc_area_bottomleft(xlb, ylb);
            ret -= calc_area_bottomleft(xub, ylb) + calc_area_bottomleft(xlb, yub);
        }

        dbgif(z <= 100, make_tuple(z, ret, xlb, xub, ylb, yub));

        for (int x : switch13.at(z)) {
            xubs.erase(xubs.lower_bound(x));
            chmax(xlb, x);
        }
        for (int y : switch23.at(z)) {
            yubs.erase(yubs.lower_bound(y));
            chmax(ylb, y);
        }
    }
    return ret;
}

int main() {
    int M;
    Problem problem;
    cin >> problem.N1 >> problem.N2 >> problem.N3 >> M;
    while (M--) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        if (u > v) swap(u, v);

        if (u == problem.s() and v == problem.t()) {
            puts("0");
            return 0;
        }

        problem.edges.emplace_back(u, v);
    }

    dbg(make_tuple(problem.N1, problem.N2, problem.N3, problem.edges));
    problem = truncate(problem);
    dbg(make_tuple(problem.N1, problem.N2, problem.N3, problem.edges));

    cout << solve(problem) << endl;
}