1 #include <queue>
  2 #include <cstdio>
  3 #include <cstring>
  4 #include <cstdlib>
  5 #include <iostream>
  6 #include <algorithm>
  7 
  8 const int MAXV=10010;
  9 const int MAXN=110;
 10 const int INF=0x3FFFFFFF;
 11 
 12 struct Edge{
 13     int from;
 14     int to;
 15     int flow;
 16     Edge* rev;
 17     Edge* next;
 18 };
 19 
 20 Edge* top;
 21 Edge* head[MAXV];
 22 
 23 int m;
 24 int n;
 25 int sum;
 26 int total;
 27 int depth[MAXV];
 28 int data[MAXN][MAXN];
 29 bool color[MAXN][MAXN];
 30 int number[MAXN][MAXN];
 31 
 32 void Initialize();
 33 void Insert(int,int,int);
 34 int Dinic(int,int);
 35 bool BFS(int,int);
 36 int DFS(int,int,int);
 37 int Convert(int,int);
 38 
 39 int main(){
 40     freopen("Excalibur.in","r",stdin);
 41     freopen("Excalibur.out","w",stdout);
 42     Initialize();
 43     printf("%d\n",sum-Dinic(0,m*n+1));
 44     return 0;
 45 }
 46 
 47 int Dinic(int s,int t){
 48     int ans=0;
 49     while(BFS(s,t)){
 50         ans+=DFS(s,INF,t);
 51     }
 52     return ans;
 53 }
 54 
 55 int DFS(int s,int flow,int t){
 56     if(s==t||flow==0)
 57         return flow;
 58     int tmp=flow;
 59     int k;
 60     for(Edge* i=head[s];i!=NULL;i=i->next){
 61         if(i->flow!=0&&tmp!=0&&depth[i->to]==depth[s]+1){
 62             k=DFS(i->to,std::min(tmp,i->flow),t);
 63             if(k==0){
 64                 depth[i->to]=0;
 65                 continue;
 66             }
 67             tmp-=k;
 68             i->flow-=k;
 69             i->rev->flow+=k;
 70             if(tmp==0)
 71                 break;
 72         }
 73     }
 74     return flow-tmp;
 75 }
 76 
 77 bool BFS(int s,int t){
 78     memset(depth,0,sizeof(depth));
 79     std::queue<int> q;
 80     depth[s]=1;
 81     q.push(s);
 82     while(!q.empty()){
 83         s=q.front();
 84         q.pop();
 85         for(Edge* i=head[s];i!=NULL;i=i->next){
 86             if(depth[i->to]==0&&i->flow!=0){
 87                 q.push(i->to);
 88                 depth[i->to]=depth[s]+1;
 89                 if(i->to==t)
 90                     return true;
 91             }
 92         }
 93     }
 94     return false;
 95 }
 96 
 97 inline void Initialize(){
 98     scanf("%d%d",&n,&m);
 99     for(int i=1;i<=n;i++){
100         for(int j=1;j<=m;j++){
101             number[i][j]=++total;
102             scanf("%d",&data[i][j]);
103             sum+=data[i][j];
104             if(i==1)
105                 color[i][j]=!color[i][j-1];
106             else
107                 color[i][j]=!color[i-1][j];
108         }
109     }
110     for(int i=1;i<=n;i++){
111         for(int j=1;j<=m;j++){
112             if(color[i][j]){
113                 Insert(0,Convert(i,j),data[i][j]);
114                 if(i>1)
115                     Insert(Convert(i,j),Convert(i-1,j),INF);
116                 if(i<n)
117                     Insert(Convert(i,j),Convert(i+1,j),INF);
118                 if(j>1)
119                     Insert(Convert(i,j),Convert(i,j-1),INF);
120                 if(j<m)
121                     Insert(Convert(i,j),Convert(i,j+1),INF);
122             }
123             else{
124                 Insert(Convert(i,j),n*m+1,data[i][j]);
125             }
126         }
127     }
128 }
129 
130 inline int Convert(int i,int j){
131     return number[i][j];
132 }
133 
134 inline void Insert(int a,int b,int flow){
135     top=new Edge;
136     Edge* tmp=top;
137     top->from=a;
138     top->to=b;
139     top->flow=flow;
140     top->next=head[a];
141     head[a]=top;
142     top=new Edge;
143     tmp->rev=top;
144     top->from=b;
145     top->to=a;
146     top->flow=0;
147     top->next=head[b];
148     head[b]=top;
149     top->rev=tmp;
150 }