Codeforces Round #FF (Div. 2)

#include <iostream>
#include <cstdio>
#include <string.h>
#include <queue>
#include <algorithm>
using namespace std;
const int maxn = 1005;
__int64 Martix[maxn][maxn],n,m,k,p;
__int64 R[maxn*1000],C[maxn*1000];
__int64 maxv(__int64 a,__int64 b)
{
      return a>b?a:b;
}
int main()
{
       priority_queue<__int64>row,cloun;
       while(scanf("%I64d%I64d%I64d%I64d",&n,&m,&k,&p)==4)
       {
            for(int i =0;i<n; ++i)
                 for(int j=0; j<m; ++j)
                   scanf("%I64d",&Martix[i][j]);
            for(int i= 0; i<n; ++i)
            {
                 __int64 a=0;
                 for(int j=0; j<m; ++j)
                     a+=Martix[i][j];
                row.push(a);
            }
            for(int i=0; i<m; ++i)
            {
                __int64 a=0;
                for(int j = 0; j<n; ++j)
                     a += Martix[j][i];
                cloun.push(a);
            }
            R[0]=0; __int64 ans=0;
            for(int i=1 ; i<=k; ++i )
            {
                 __int64 rt =row.top();row.pop();
                 ans+=rt;
                 R[i]=ans;
                 rt-=m*p;
                 row.push(rt);
            }
            C[0]=0;
            ans=0;
            for(int i =1; i<=k; ++i)
            {
                 __int64 rt =cloun.top();cloun.pop();
                 ans+=rt;
                 rt-=n*p;
                 C[i]=ans;
                 cloun.push(rt);
            }
            ans=-1000000000000000000;
            for(__int64 i =0; i<=k; ++i)
                {
                      __int64 t = R[i]+C[k-i];
                      __int64 e = p*i*(k-i);
                      t =t-e;
                      ans=maxv(ans,t);
                }
           printf("%I64d\n",ans);
          while(!row.empty())row.pop();
          while(!cloun.empty())cloun.pop();
       }

       return 0;
}