#include<stdio.h>
#include<string.h>
int n,m;
int a[1005][1005];
int ans[1005][1005];

int fun(int x,int y)
{
    if(x+y==3) return a[1][1]*a[x][y];
    int res;
    int min=-1;
    if(x>1)
    {
        res=a[x][y]*a[x-1][y];
        if(x>2&&((min>res+ans[x-2][y])||min==-1)) min=res+ans[x-2][y];
        if(y>1&&((min>res+ans[x-1][y-1])||min==-1)) min=res+ans[x-1][y-1];
    }
    if(y>1)
    {
        res=a[x][y]*a[x][y-1];
        if(y>2&&((min>res+ans[x][y-2])||min==-1)) min=res+ans[x][y-2];
        if(x>1&&((min>res+ans[x-1][y-1])||min==-1)) min=res+ans[x-1][y-1];
    }
    return min;
}

int main()
{
    int i,j,k;
    while(scanf("%d %d",&n,&m)!=EOF)
    {
        memset(ans,-1,sizeof(ans));
        for(i=1;i<=n;i++)
        {
            for(j=1;j<=m;j++)
            {
                scanf("%d",&a[i][j]);
            }
        }
        for(i=2;i<=m;i+=2)
        {
            for(j=1;j<=i;j++)
            {
                ans[j][i+1-j]=fun(j,i+1-j);
            }
        }
        k=i;
        if(i==m+1) i=2;
        else i=3;
        for(;i<=n;i+=2,k+=2)
        {
            for(j=m;j>=k-m;j--)
            {
                ans[k+1-j][j]=fun(k+1-j,j);
            }
        }
        printf("%d\n",ans[n][m]);
    }
    return 0;
}
/*
4 3
1 2 3
2 2 1
1 2 3
2 2 1

3 4
1 2 1 2
2 2 2 2
3 1 3 1

3 4
1 2 3 4
2 3 4 5
3 4 5 6
*/