#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int FFTMOD = 119 << 23 | 1;
const int INF = (int)1e9 + 23111992;
const long long LINF = (long long)1e18 + 23111992;
const long double PI = acos((long double)-1);
const long double EPS = 1e-9;
inline long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
inline long long fpow(long long n, long long k, int p = MOD) {
  long long r = 1;
  for (; k; k >>= 1) {
    if (k & 1) r = r * n % p;
    n = n * n % p;
  }
  return r;
}
template <class T>
inline int chkmin(T& a, const T& val) {
  return val < a ? a = val, 1 : 0;
}
template <class T>
inline int chkmax(T& a, const T& val) {
  return a < val ? a = val, 1 : 0;
}
inline unsigned long long isqrt(unsigned long long k) {
  unsigned long long r = sqrt(k) + 1;
  while (r * r > k) r--;
  return r;
}
inline long long icbrt(long long k) {
  long long r = cbrt(k) + 1;
  while (r * r * r > k) r--;
  return r;
}
inline void addmod(int& a, int val, int p = MOD) {
  if ((a = (a + val)) >= p) a -= p;
}
inline void submod(int& a, int val, int p = MOD) {
  if ((a = (a - val)) < 0) a += p;
}
inline int mult(int a, int b, int p = MOD) { return (long long)a * b % p; }
inline int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
inline int sign(long double x) { return x < -EPS ? -1 : x > +EPS; }
inline int sign(long double x, long double y) { return sign(x - y); }
mt19937 mt(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int myrand() { return abs((int)mt()); }
struct node_t {
  node_t *p, *l, *r;
  int size, rev;
  int s, w;
  node_t() : p(0), l(0), r(0), size(1), rev(0), s(0), w(1) {}
};
int isrt(node_t* x) { return !(x->p) || (x->p->l != x && x->p->r != x); }
int left(node_t* x) { return x->p->l == x; }
void setchild(node_t* x, node_t* p, int l) {
  (l ? p->l : p->r) = x;
  if (x) x->p = p;
}
void push(node_t* x) {
  node_t* u = x->l;
  node_t* v = x->r;
  if (x->rev) {
    if (u) swap(u->l, u->r), u->rev ^= 1;
    if (v) swap(v->l, v->r), v->rev ^= 1;
    x->rev = 0;
  }
}
int size(node_t* x) { return x ? x->size : 0; }
int sum(node_t* x) { return x ? x->s : 0; }
void pull(node_t* x) {
  x->size = size(x->l) + 1 + size(x->r);
  x->s = sum(x->l) + x->w + sum(x->r);
}
void rotate(node_t* x) {
  node_t *p = x->p, *g = p->p;
  int l = left(x);
  setchild(l ? x->r : x->l, p, l);
  if (!isrt(p))
    setchild(x, g, left(p));
  else
    x->p = g;
  setchild(p, x, !l);
  pull(p);
}
node_t* splay(node_t* x) {
  push(x);
  while (!isrt(x)) {
    node_t *p = x->p, *g = p->p;
    if (g) push(g);
    push(p), push(x);
    if (!isrt(p)) rotate(left(x) != left(p) ? x : p);
    rotate(x);
  }
  pull(x);
  return x;
}
node_t* access(node_t* x) {
  node_t* z = 0;
  for (node_t* y = x; y; y = y->p) {
    splay(y);
    y->w += sum(y->r);
    y->r = z;
    y->w -= sum(y->r);
    pull(z = y);
  }
  splay(x);
  return z;
}
void link(node_t* x, node_t* p) {
  access(x), access(p);
  x->p = p;
  p->w += sum(x);
}
void cut(node_t* x) {
  access(x);
  x->l->p = 0, x->l = 0;
  pull(x);
}
void makeroot(node_t* x) {
  access(x);
  x->rev ^= 1;
  swap(x->l, x->r);
}
node_t* findroot(node_t* x) {
  access(x);
  while (x->l) push(x), x = x->l;
  push(x);
  return splay(x);
}
node_t* lca(node_t* x, node_t* y) {
  if (findroot(x) != findroot(y)) return 0;
  access(x);
  return access(y);
}
int connect(node_t* x, node_t* y) {
  if (x == y) return 1;
  access(x), access(y);
  return x->p != 0;
}
int treequery(node_t* x) {
  access(x);
  return x->w;
}
const int maxn = 2e5 + 5;
int n, m;
vector<vector<int> > a;
node_t pool[maxn];
void makeroot(int u) { makeroot(pool + u); }
void link(int u, int v) { link(pool + u, pool + v); }
void cut(int u) { cut(pool + u); }
int findroot(int u) { return findroot(pool + u) - pool; }
int lca(int u, int v) {
  node_t* a = lca(pool + u, pool + v);
  if (!a) return -1;
  return a - pool;
}
int connect(int u, int v) { return connect(pool + u, pool + v); }
int treequery(int u) { return treequery(pool + u); }
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
int inside(int u, int v) {
  if (!(0 <= u && u < n)) return 0;
  if (!(0 <= v && v < m)) return 0;
  return 1;
}
pair<int, int> merge(pair<int, int> a, pair<int, int> b) {
  pair<int, int> res = make_pair(min(a.first, b.first), 0);
  if (res.first == a.first) {
    res.second += a.second;
  }
  if (res.first == b.first) {
    res.second += b.second;
  }
  return res;
}
pair<int, int> st[maxn << 2];
int lz[maxn << 2];
void build(int p, int L, int R) {
  if (L == R) {
    st[p] = make_pair(0, 1);
    return;
  }
  build(p << 1, L, L + R >> 1);
  build(p << 1 | 1, (L + R >> 1) + 1, R);
  st[p] = merge(st[p << 1], st[p << 1 | 1]);
}
void push(int p, int L, int R) {
  if (lz[p]) {
    st[p].first += lz[p];
    if (L < R) {
      for (int i = (0); i < (2); ++i) {
        lz[p << 1 | i] += lz[p];
      }
    }
    lz[p] = 0;
  }
}
void upd(int p, int l, int r, int L, int R, int val) {
  push(p, L, R);
  if (R < l || r < L) return;
  if (l <= L && R <= r) {
    lz[p] = val;
    push(p, L, R);
    return;
  }
  upd(p << 1, l, r, L, L + R >> 1, val);
  upd(p << 1 | 1, l, r, (L + R >> 1) + 1, R, val);
  st[p] = merge(st[p << 1], st[p << 1 | 1]);
}
pair<int, int> query(int p, int l, int r, int L, int R) {
  push(p, L, R);
  if (R < l || r < L) return make_pair(INF, 1);
  if (l <= L && R <= r) {
    return st[p];
  }
  return merge(query(p << 1, l, r, L, L + R >> 1),
               query(p << 1 | 1, l, r, (L + R >> 1) + 1, R));
}
void chemthan() {
  cin >> n >> m;
  a.resize(n, vector<int>(m));
  vector<pair<int, int> > from(n * m + 1);
  for (int i = (0); i < (n); ++i)
    for (int j = (0); j < (m); ++j)
      cin >> a[i][j], from[a[i][j]] = make_pair(i, j);
  build(1, 1, n * m);
  long long res = 0;
  int ptr = 1;
  vector<vector<int> > adj(n * m + 1);
  for (int i = (1); i < (n * m + 1); ++i) {
    int x = from[i].first;
    int y = from[i].second;
    upd(1, 1, i, 1, n * m, 1);
    for (int d = (0); d < (4); ++d) {
      int nx = x + dx[d];
      int ny = y + dy[d];
      vector<int> vals;
      if (inside(nx, ny) && ptr <= a[nx][ny] && a[nx][ny] < i) {
        vals.push_back(a[nx][ny]);
      }
      sort((vals).begin(), (vals).end());
      for (int x : vals) {
        while (ptr <= x && findroot(x) == i) {
          for (int y : adj[ptr]) {
            makeroot(y);
            if (findroot(ptr) == y) {
              cut(ptr);
            }
          }
          makeroot(i);
          ptr++;
        }
        if (ptr <= x) {
          makeroot(x);
          link(x, i);
          adj[x].push_back(i);
          upd(1, ptr, x, 1, n * m, -1);
        }
      }
    }
    res += query(1, ptr, i, 1, n * m).second;
  }
  cout << res << "\n";
}
int main(int argc, char* argv[]) {
  ios_base::sync_with_stdio(0), cin.tie(0);
  if (argc > 1) {
    assert(freopen(argv[1], "r", stdin));
  }
  if (argc > 2) {
    assert(freopen(argv[2], "wb", stdout));
  }
  chemthan();
  cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
  return 0;
}
