#line 1 "library/Template/template.hpp"
#include <bits/stdc++.h>
using namespace std;

#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define ALL(v) (v).begin(),(v).end()
#define UNIQUE(v) sort(ALL(v)),(v).erase(unique(ALL(v)),(v).end())
#define SZ(v) (int)v.size()
#define MIN(v) *min_element(ALL(v))
#define MAX(v) *max_element(ALL(v))
#define LB(v,x) int(lower_bound(ALL(v),(x))-(v).begin())
#define UB(v,x) int(upper_bound(ALL(v),(x))-(v).begin())

using ll=long long int;
using ull=unsigned long long;
const int inf = 0x3fffffff;
const ll INF = 0x1fffffffffffffff;

template<typename T>inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<typename T>inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<typename T,typename U>T ceil(T x,U y){assert(y!=0); if(y<0)x=-x,y=-y; return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>T floor(T x,U y){assert(y!=0); if(y<0)x=-x,y=-y; return (x>0?x/y:(x-y+1)/y);}
template<typename T>int popcnt(T x){return __builtin_popcountll(x);}
template<typename T>int topbit(T x){return (x==0?-1:63-__builtin_clzll(x));}
template<typename T>int lowbit(T x){return (x==0?-1:__builtin_ctzll(x));}
#line 2 "library/Utility/fastio.hpp"
#include <unistd.h>

class FastIO{
    static constexpr int L=1<<16;
    char rdbuf[L];
    int rdLeft=0,rdRight=0;
    inline void reload(){
        int len=rdRight-rdLeft;
        memmove(rdbuf,rdbuf+rdLeft,len);
        rdLeft=0,rdRight=len;
        rdRight+=fread(rdbuf+len,1,L-len,stdin);
    }
    inline bool skip(){
        for(;;){
            while(rdLeft!=rdRight and rdbuf[rdLeft]<=' ')rdLeft++;
            if(rdLeft==rdRight){
                reload();
                if(rdLeft==rdRight)return false;
            }
            else break;
        }
        return true;
    }
    template<typename T,enable_if_t<is_integral<T>::value,int> =0>inline bool _read(T& x){
        if(!skip())return false;
        if(rdLeft+20>=rdRight)reload();
        bool neg=false;
        if(rdbuf[rdLeft]=='-'){
            neg=true;
            rdLeft++;
        }
        x=0;
        while(rdbuf[rdLeft]>='0' and rdLeft<rdRight){
            x=x*10+(neg?-(rdbuf[rdLeft++]^48):(rdbuf[rdLeft++]^48));
        }
        return true;
    }
    inline bool _read(__int128_t& x){
        if(!skip())return false;
        if(rdLeft+40>=rdRight)reload();
        bool neg=false;
        if(rdbuf[rdLeft]=='-'){
            neg=true;
            rdLeft++;
        }
        x=0;
        while(rdbuf[rdLeft]>='0' and rdLeft<rdRight){
            x=x*10+(neg?-(rdbuf[rdLeft++]^48):(rdbuf[rdLeft++]^48));
        }
        return true;
    }
    inline bool _read(__uint128_t& x){
        if(!skip())return false;
        if(rdLeft+40>=rdRight)reload();
        x=0;
        while(rdbuf[rdLeft]>='0' and rdLeft<rdRight){
            x=x*10+(rdbuf[rdLeft++]^48);
        }
        return true;
    }
    template<typename T,enable_if_t<is_floating_point<T>::value,int> =0>inline bool _read(T& x){
        if(!skip())return false;
        if(rdLeft+20>=rdRight)reload();
        bool neg=false;
        if(rdbuf[rdLeft]=='-'){
            neg=true;
            rdLeft++;
        }
        x=0;
        while(rdbuf[rdLeft]>='0' and rdbuf[rdLeft]<='9' and rdLeft<rdRight){
            x=x*10+(rdbuf[rdLeft++]^48);
        }
        if(rdbuf[rdLeft]!='.')return true;
        rdLeft++;
        T base=.1;
        while(rdbuf[rdLeft]>='0' and rdbuf[rdLeft]<='9' and rdLeft<rdRight){
            x+=base*(rdbuf[rdLeft++]^48);
            base*=.1;
        }
        if(neg)x=-x;
        return true;
    }
    inline bool _read(char& x){
        if(!skip())return false;
        if(rdLeft+1>=rdRight)reload();
        x=rdbuf[rdLeft++];
        return true;
    }
    inline bool _read(string& x){
        if(!skip())return false;
        for(;;){
            int pos=rdLeft;
            while(pos<rdRight and rdbuf[pos]>' ')pos++;
            x.append(rdbuf+rdLeft,pos-rdLeft);
            if(rdLeft==pos)break;
            rdLeft=pos;
            if(rdLeft==rdRight)reload();
            else break;
        }
        return true;
    }
    template<typename T>inline bool _read(vector<T>& v){
        for(auto& x:v){
            if(!_read(x))return false;
        }
        return true;
    }

    char wtbuf[L],tmp[50];
    int wtRight=0;
    inline void _write(const char& x){
        if(wtRight>L-32)flush();
        wtbuf[wtRight++]=x;
    }
    inline void _write(const string& x){
        for(auto& c:x)_write(c);
    }
    template<typename T,enable_if_t<is_integral<T>::value,int> =0>inline void _write(T x){
        if(wtRight>L-32)flush();
        if(x==0){
            _write('0');
            return;
        }
        else if(x<0){
            _write('-');
            if (__builtin_expect(x == std::numeric_limits<T>::min(), 0)) {
                switch (sizeof(x)) {
                case 2: _write("32768"); return;
                case 4: _write("2147483648"); return;
                case 8: _write("9223372036854775808"); return;
                }
            }
            x=-x;
        }
        int pos=0;
        while(x!=0){
            tmp[pos++]=char((x%10)|48);
            x/=10;
        }
        rep(i,0,pos)wtbuf[wtRight+i]=tmp[pos-1-i];
        wtRight+=pos;
    }
    inline void _write(__int128_t x){
        if(wtRight>L-40)flush();
        if(x==0){
            _write('0');
            return;
        }
        else if(x<0){
            _write('-');
            x=-x;
        }
        int pos=0;
        while(x!=0){
            tmp[pos++]=char((x%10)|48);
            x/=10;
        }
        rep(i,0,pos)wtbuf[wtRight+i]=tmp[pos-1-i];
        wtRight+=pos;
    }
    inline void _write(__uint128_t x){
        if(wtRight>L-40)flush();
        if(x==0){
            _write('0');
            return;
        }
        int pos=0;
        while(x!=0){
            tmp[pos++]=char((x%10)|48);
            x/=10;
        }
        rep(i,0,pos)wtbuf[wtRight+i]=tmp[pos-1-i];
        wtRight+=pos;
    }
    inline void _write(double x){
        ostringstream oss;
        oss << fixed << setprecision(15) << double(x);
        string s = oss.str();
        _write(s);
    }
    template<typename T>inline void _write(const vector<T>& v){
        rep(i,0,v.size()){
            if(i)_write(' ');
            _write(v[i]);
        }
    }
public:
    FastIO(){}
    ~FastIO(){flush();}
    inline void read(){}
    template <typename Head, typename... Tail>inline void read(Head& head,Tail&... tail){
        assert(_read(head));
        read(tail...); 
    }
    template<bool ln=true,bool space=false>inline void write(){if(ln)_write('\n');}
    template <bool ln=true,bool space=false,typename Head, typename... Tail>inline void write(const Head& head,const Tail&... tail){
        _write(head);
        write<ln,true>(tail...); 
        if(space)_write(' ');
    }
    inline void flush(){
        fwrite(wtbuf,1,wtRight,stdout);
        wtRight=0;
    }
};

/**
 * @brief Fast IO
 */
#line 3 "sol.cpp"

#line 2 "library/Graph/mincostflow.hpp"

template<typename Flow,typename Cost,bool Maximize=false>class MinCostFlow{
    struct ptr{int v_id,e_id;};
    struct edge{
        int from,to; Flow flow,cap; Cost weight; int rev;
        edge(int _f,int _t,Flow _c,Cost _w,int _r)
            :from(_f),to(_t),flow(0),cap(_c),weight(_w),rev(_r){}
        Flow residual_cap()const{return cap-flow;}
    };
    int n; vector<vector<edge>> g;
    vector<Flow> b,pot; vector<ptr> ptrs;
    Cost farthest; vector<Cost> dist; vector<edge*> par;
    vector<int> exc,def;
    void push(edge& e,Flow amount){
        e.flow+=amount; g[e.to][e.rev].flow-=amount;
    }
    Cost residual_cost(int from,int to,edge& e){
        return e.weight+pot[from]-pot[to];
    }
    bool dual(const Flow& delta){
        dist.assign(n,numeric_limits<Cost>::max()); par.assign(n,nullptr);
        exc.erase(remove_if(ALL(exc),[&](int v){return b[v]<delta;}),exc.end());
        def.erase(remove_if(ALL(def),[&](int v){return b[v]>-delta;}),def.end());
        priority_queue<pair<Cost,int>,vector<pair<Cost,int>>,greater<>> pq;
        for(auto& v:exc)pq.push({dist[v]=0,v});
        farthest=0; int def_cnt=0;
        while(!pq.empty()){
            auto [d,u]=pq.top(); pq.pop();
            if(dist[u]<d)continue;
            farthest=d;
            if(b[u]<=-delta)def_cnt++;
            if(def_cnt>=(int)def.size())break;
            for(auto& e:g[u]){
                if(e.residual_cap()<delta)continue;
                int v=e.to; Cost nd=d+residual_cost(u,v,e);
                if(nd>=dist[v])continue;
                pq.push({dist[v]=nd,v}); par[v]=&e;
            }
        }
        rep(v,0,n)pot[v]+=min(dist[v],farthest);
        return def_cnt>0;
    }
    void primal(const Flow& delta){
        for(auto& t:def){
            if(dist[t]>farthest)continue;
            Flow f=-b[t]; int v;
            for(v=t;par[v]!=nullptr;v=par[v]->from){
                chmin(f,par[v]->residual_cap());
            }
            chmin(f,b[v]); f-=f%delta;
            if(f<=0)continue;
            for(v=t;par[v]!=nullptr;){
                auto& e=*par[v];
                push(e,f);
                int u=par[v]->from;
                if(e.residual_cap()<=0)par[v]=nullptr;
                v=u;
            }
            b[t]+=f; b[v]-=f;
        }
    }
public:
    MinCostFlow(int _n):n(_n),g(_n),b(_n),pot(_n){}
    void add_edge(int from,int to,Flow lb,Flow ub,Cost cost){
        int f_id=g[from].size(),t_id=(from==to?f_id+1:g[to].size());
        g[from].push_back(edge(from,to,ub,Maximize?-cost:cost,t_id));
        g[to].push_back(edge(to,from,-lb,Maximize?cost:-cost,f_id));
        ptrs.push_back(ptr{from,f_id});
    }
    void add_supply(int v,Flow amount){b[v]+=amount;}
    void add_demand(int v,Flow amount){b[v]-=amount;}
    Flow get_pot(int v){return pot[v];}
    Flow get_flow(int v){return g[ptrs[v].v_id][ptrs[v].e_id].flow;}
    template<typename T=ll>pair<bool,T> run(const Flow& sf=2){
        Flow max_flow=1;
        for(auto& t:b)chmax(max_flow,abs(t));
        for(auto& es:g)for(auto& e:es)chmax(max_flow,abs(e.residual_cap()));
        Flow delta=1;
        while(delta<max_flow)delta*=sf;
        for(;delta;delta/=sf){
            for(auto& es:g)for(auto& e:es){
                Flow rcap=e.residual_cap();
                rcap-=rcap%delta;
                Cost rcost=residual_cost(e.from,e.to,e);
                if(rcost<0 or rcap<0){
                    push(e,rcap);
                    b[e.from]-=rcap; b[e.to]+=rcap;
                }
            }
            rep(v,0,n)if(b[v]!=0){
                (b[v]>0?exc:def).push_back(v);
            }
            while(dual(delta))primal(delta);
        }
        T res=0;
        for(auto& es:g)for(auto& e:es)res+=T(e.flow)*T(e.weight);
        res>>=1;
        if(exc.empty() and def.empty())return {1,Maximize?-res:res};
        else return {0,Maximize?-res:res};
    }
};

/**
 * @brief Minimum Cost b-flow
 */
#line 5 "sol.cpp"

FastIO io;
int main() {
    int n, m, k, L;
    io.read(n, m, k, L);
    vector<int> x(L), y(L), z(L);
    rep(i, 0, L) { io.read(x[i], y[i], z[i]); }

    MinCostFlow<ll, ll, 1> buf(n + m + 1);
    int S = n + m;
    rep(i, 0, n) { buf.add_edge(S, i, 0, 1, 0); }
    rep(i, 0, m) { buf.add_edge(n + i, S, 0, 1, 0); }
    rep(i, 0, L) { buf.add_edge(x[i] - 1, y[i] - 1 + n, 0, 1, 1 << z[i]); }
    auto [_, ret] = buf.run();
    io.write(ret);
    return 0;
}