RoadCut

#include<stdio.h>

int main()
{
    int n,m;
    scanf("%d %d",&n,&m);
    int TopDown[m+2];for(int i=1;i<=m+1;i++)TopDown[i] = 0;
    int RightLeft[n+2];for(int i=1;i<=n+1;i++)RightLeft[i] = 0;
    int sum = 0;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            int val;
            scanf("%d",&val);
            RightLeft[i] += val;
            TopDown[j] += val;
            sum += val;
        }
    }
    int ans = -2e9;
    int TopDownADD[m+2];for(int i=0;i<=m+1;i++)TopDownADD[i] = 0;
    int RightLeftADD[n+2];for(int i=0;i<=n+1;i++)RightLeftADD[i] = 0;

    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            int addval;
            scanf("%d",&addval);
            TopDownADD[j] += addval;
            RightLeftADD[i] += addval;
        }
    }

    for(int i=1;i<=n;i++){
        int newsum = sum - RightLeft[i] + RightLeftADD[i-1] + RightLeftADD[i+1];
        if(newsum >= ans)ans = newsum;
    }
    for(int i=1;i<=m;i++){
        int newsum = sum - TopDown[i] + TopDownADD[i-1] + TopDownADD[i+1];
        if(newsum >= ans)ans = newsum;
    }
    printf("%d",ans);
    return 0;
}