#include <cstdio>
#include <cmath>
#include <iostream>
#include <cstring>

using namespace std;

int a[1005][1005];
int n,m;
int dp[1005][1005];

void input() {
    for(int i = 1 ; i <= n ; i ++) 
    for(int j = 1 ; j <= m ; j ++)
    scanf("%d",&a[i][j]);    
    memset(dp,0x3f,sizeof(dp));
    dp[1][2] = a[1][1] * a[1][2];
    dp[2][1] = a[1][1] * a[2][1];
    for(int i = 1 ; i <= n ; i ++) {
        for(int j = 1 ; j <= m ;j ++) {
            if(i + j <= 3) continue;
            if((i+j)%2==0) {
                dp[i][j] = min(dp[i-1][j],dp[i][j-1]);
            }
            else {
                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]);
                }
            }
        }
    }
    printf("%d\n",dp[n][m]);
}

void solve() {

}

int main(void) {
    //freopen("a.in","r",stdin);
    while(~scanf("%d %d",&n,&m)) {
        input();
        solve();
    }
}