#include "bits/stdc++.h"
#include "atcoder/all"
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
//const bool debug = false;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
bool comp(const P& lh, const P& rh) {
	if (lh.second != rh.second)return lh.second < rh.second;
	return lh.first < rh.first;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int h, w, n; cin >> h >> w >> n;
	vector<vector<int>> c(h, vector<int>(w));
	rep(i, h)rep(j, w)cin >> c[i][j];
	vector<P>vp;
	rep(i, h)rep(j, w) {
		int ni, nj, x, y;
		if (j != w - 1) {
			ni = i; nj = j + 1;
			x = c[i][j] - 1; y = c[ni][nj] - 1;
			if (x != y) vp.push_back({ min(x,y),max(x,y) });
		}
		if (i != h - 1) {
			ni = i + 1; nj = j;
			x = c[i][j] - 1; y = c[ni][nj] - 1;
			if (x != y) vp.push_back({ min(x,y),max(x,y) });
		}
	}
	sort(all(vp), comp);
	vp.erase(unique(all(vp)), vp.end());
	//cout << vp.size() << endl;
	fenwick_tree<int> fw(n - 1);
	rep(i, vp.size()) {
		int l = vp[i].first;
		int r = vp[i].second;
		//cout << l << " " << r << endl;
		int x = fw.sum(l, r);
		if (0 != x)continue;
		//cout << r - 1 << endl;
		fw.add(r - 1, 1);
	}
	cout << 1 + fw.sum(0, n - 1) << endl;
	return 0;
}