#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;
typedef tuple<int, int, int> T;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
        size_t seed = hash<T>()(x.first);
        return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const int inf = 1e9 + 9;
const ll mod = 1e9 + 7;
const double eps = 1e-8;
const double pi = acos(-1);

int w, h;
int m[110][110];

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0,-1,  0};

bool used[110][110][10];

bool is_kadomatsu(int p, int q, int r) {
    return (p < q && q > r && p != r) || (p > q && q < r && p != r) || p == 0 || q == 0 || r == 0;
}

int solve() {
    queue<T> que;
    queue<int> dis;
    used[0][0][0] = true;
    que.push(make_tuple(0, 0, 0));
    dis.push(0);
    while (!que.empty()) {
        T t = que.front(); que.pop();
        int y = get<0>(t), x = get<1>(t), p = get<2>(t);
        int d = dis.front(); dis.pop();
        if (y == h-1 && x == w-1) return d;
        for (int i = 0; i < 4; i++) {
            int Y = y + dy[i], X = x + dx[i];
            if (0 <= Y && Y < h && 0 <= X && X < w && !used[Y][X][m[y][x]] && is_kadomatsu(p, m[y][x], m[Y][X])) {
                used[Y][X][m[y][x]] = true;
                que.push(make_tuple(Y, X, m[y][x]));
                dis.push(d+1);
            }
        }       
    }
    return -1;
}

void input() {
    cin >> w >> h;
    for (int i = 0; i < h; i++)
        for (int j = 0; j < w; j++)
            cin >> m[i][j];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    input();
    cout << solve() << endl;
}