#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = l; i <= r; i++)
using namespace std;
typedef long long ll;
const int N = 105;
const int M = N * N;
const int inf = 1e8;

int h, w, tot;
int a[N][N];
vector<int> E[M], E2[M];
set<pair<int, int>> edges;
bool bfsed[M];
int dis[M], tmp[M];
void bfs(int s) {
    assert(!bfsed[s]);
    bfsed[s] = true;
    rep(i, 1, tot) { tmp[i] = inf; }
    tmp[s] = 0;
    queue<int> q;
    q.push(s);
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (auto v : E[u]) {
            if (tmp[v] == inf) {
                tmp[v] = tmp[u] + 1;
                q.push(v);
            }
        }
    }
    rep(i, 1, tot) {
        // printf("%d ", tmp[i]);
        dis[i] += tmp[i];
    }
    // printf("\n");
}
void bfs2() {
    rep(i, 1, tot) { tmp[i] = inf; }
    queue<int> q;
    tmp[tot] = 0;
    q.push(tot);

    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (auto v : E2[u]) {
            if (tmp[v] == inf) {
                tmp[v] = tmp[u] + 1;
                q.push(v);
            }
        }
    }
    rep(i, 1, tot) {
        // printf("%d ", tmp[i]);
        dis[i] += tmp[i];
    }
    // printf("\n");
}

int main() {
    scanf("%d%d", &h, &w);
    rep(i, 1, h) {
        rep(j, 1, w) { scanf("%d", &a[i][j]); }
    }
    edges.clear();

    rep(i, 1, h - 1) {
        rep(j, 1, w) {
            int u = a[i][j], v = a[i + 1][j];
            if (u != v && !edges.count(make_pair(u, v))) {
                edges.insert(make_pair(u, v));
                E[u].push_back(v);
                E2[v].push_back(u);
            }
        }
    }
    tot = h * w + 1;
    rep(j, 1, w) {
        int u = a[h][j];
        if (!edges.count(make_pair(u, tot))) {
            edges.insert(make_pair(u, tot));
            E[u].push_back(tot);
            E2[tot].push_back(u);
        }
    }
    rep(i, 1, tot) bfsed[i] = false;
    rep(j, 1, w) {
        int u = a[1][j];
        if (!bfsed[u]) bfs(u);
    }
    bfs2();
    int ans = inf;
    rep(i, 1, tot) { ans = min(ans, dis[i]); }
    printf("%d\n", ans);
    return 0;
}