#include <cstdio>
#include <iostream>
#include <cstring>
#include <queue>
#include <algorithm>
using namespace std;

int maxn = 1000 + 5;
int a[1009][1009];
int dp[1009][1009];
int n, m;

int main()
{
    while(scanf("%d%d", &n, &m) == 2) {
        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= m; j++) {
                scanf("%d", &a[i][j]);
            }
        }

        for(int i = 0; i <= n; i++) {
            for(int j = 0; j <= m; j++) {
                dp[i][j] = 0;
            }
        }

        for(int i = 1; i <= m; i++) {
            if(i % 2 == 0) {
                dp[1][i] = dp[1][i-1] + a[1][i-1]*a[1][i];

            } else {
                dp[1][i] = dp[1][i-1];
            }
        }

        for(int i = 1; i <= n; i++) {
            if(i % 2 == 0) {
                dp[i][1] = dp[i-1][1] + a[i-1][1]*a[i][1];
            } else {
                dp[i][1] = dp[i-1][1];
            }
        }
        for(int i = 2; i <= n; i++) {
            for(int j = 2; j <= m; j++) {
                int t = i + j;
                if(t % 2 == 0) {
                    if(dp[i][j-1] < dp[i-1][j]) dp[i][j] = dp[i][j-1];
                    else dp[i][j] = dp[i-1][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]);
                }
            }
        }
        cout << dp[n][m] << endl;
    }
    return 0;
}