#include<iostream>
#include<cstdio>
#include<cstring>
#include<cctype>
#include<cmath>
#include<vector>
#include<queue>
#include<map>
#include<algorithm>
#include<set>
#define scnaf scanf
#define cahr char
#define bug puts("bugbugbug");
using namespace std;
typedef long long ll;
const int mod=1000000007;
const int maxn=1000+5;
const int inf=1e9;
int a[maxn][maxn]={0};
ll dp[maxn][maxn];
int main()
{
   int n,m;
   while(~scanf("%d%d",&n,&m))
   {
       memset(dp,0,sizeof(dp));
       for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++){
            scanf("%d",&a[i][j]);
        }
        for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
        {
           if((i+j)%2) {
           if(i==1) dp[i][j]=dp[i][j-1]+a[i][j-1]*a[i][j];
           else if(j==1) dp[i][j]=dp[i-1][j]+a[i-1][j]*a[i][j];
           else dp[i][j]=min(dp[i-1][j]+a[i-1][j]*a[i][j],dp[i][j-1]+a[i][j-1]*a[i][j]);
           }
           else{
           if(i==1&&j==1) continue;
           if(i==1) dp[i][j]=dp[i][j-1];
           else if(j==1) dp[i][j]=dp[i-1][j];
           else dp[i][j]=min(dp[i-1][j],dp[i][j-1]);
           }
        }
        printf("%I64d\n",dp[n][m]);
   }
}