amonamarthfkingrocks

#include <bits/stdc++.h>
using namespace std;

int h, w, len = -1, ip = -99, jp = -99;
int a[2002][2002];
pair<bool,int> vis[2002][2002];

void visita (int i, int j)
{
    len++;

    if (vis[i][j].first){
        cout << len + vis[i][j].second;
        exit(0);
    }

    vis[i][j].first = 1;
    vis[i][j].second = len;

    int imin, jmin, mini;
    bool esiste = 0;

    if (a[i-1][j] != -1 && (ip != i-1 || jp != j)){
        esiste = 1;
        imin = i-1;
        jmin = j;
        mini = abs(a[i][j] - a[i-1][j]);
    }
    if (a[i+1][j] != -1 && (ip != i+1 || jp != j)){
        if (!esiste){
            esiste = 1;
            imin = i+1;
            jmin = j;
            mini = abs(a[i][j] - a[i+1][j]);
        } else{
            if (abs(a[i][j] - a[i+1][j]) < mini){
                mini = abs(a[i][j] - a[i+1][j]);
                imin = i+1;
                jmin = j;
            } else if (abs(a[i][j] - a[i+1][j]) < mini){
                if (a[i+1][j] < a[imin][jmin]){
                    imin = i+1;
                    jmin = j;
                }
            }
        }

    }
    if (a[i][j-1] != -1 && (ip != i || jp != j-1)){
        if (!esiste){
            esiste = 1;
            imin = i;
            jmin = j-1;
            mini = abs(a[i][j] - a[i][j-1]);
        } else{
            if (abs(a[i][j] - a[i][j-1]) < mini){
                mini = abs(a[i][j] - a[i][j-1]);
                imin = i;
                jmin = j-1;
            } else if (abs(a[i][j] - a[i][j-1]) < mini){
                if (a[i][j-1] < a[imin][jmin]){
                    imin = i;
                    jmin = j-1;
                }
            }
        }

    }
    if (a[i][j+1] != -1 && (ip != i || jp != j+1)){
        if (abs(a[i][j] - a[i][j+1]) < mini){
                mini = abs(a[i][j] - a[i][j+1]);
                imin = i;
                jmin = j+1;
            } else if (abs(a[i][j] - a[i][j+1]) < mini){
                if (a[i][j+1] < a[imin][jmin]){
                    imin = i;
                    jmin = j+1;
                }
            }
        }

    ip = i, jp = j;
    visita(imin, jmin);
}


int main()
{
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    ios_base::sync_with_stdio(!!false);

    cin >> h >> w;

    if(h==1 && w==1){
        cout << 0;
        return 0;
    }

    for (int i=1; i<=h; i++)
        for (int j=1; j<=w; j++)
            cin >> a[i][j];


    for (int i=0; i<=h+1; i++){
        a[i][0] = -1;
        a[i][w+1] = -1;
    }

    for (int i=0; i<=w+1; i++){
        a[0][i] = -1;
        a[h+1][i] = -1;
    }

    visita(1,1);

    return 0;
}