// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <cmath>
#include <iomanip>
#define dibs reserve
#define OVER9000 1234567890
#define patkan 9
#define tisic 47
#define soclose 1e-9
#define pi 3.1415926535898
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define chocolate win
#define ff first
#define ss second
#define abs(x) ((x < 0)?-(x):(x))
#define uint unsigned int
// mylittlepony
using namespace std;

struct infoE {
	int a,b,d;

	bool operator<(const infoE &E) const {
		return d < E.d;}
	};

int main() {
//	freopen("skilevel.in","r",stdin);
//	freopen("skilevel.out","w",stdout);
	int N,M,T;
	scanf(" %d %d %d",&N,&M,&T);
	vector< vector<int> > H(N, vector<int>(M));
	for(int i =0; i < N*M; i++) scanf(" %d",&H[i/M][i%M]);

	vector<infoE> E;
	vector<int> D(N*M);
	int dx[] ={1,-1,0,0};
	int dy[] ={0,0,1,-1};
	for(int i =0; i < N*M; i++) for(int k =0; k < 4; k++) {
		int x =i/M+dx[k], y =i%M+dy[k];
		if(x < 0 || y < 0 || x >= N || y >= M) continue;
		infoE I;
		I.a =x*M+y;
		I.b =i;
		I.d =abs(H[i/M][i%M]-H[x][y]);
		E.push_back(I);}
	sort(E.begin(),E.end());

	vector< vector<int> > C(N*M);
	vector<int> isC(N*M);
	for(int i =0; i < N*M; i++) {
		C[i].resize(1,i);
		isC[i] =i;}

	for(uint e =0; e < E.size(); e++) {
		int x =E[e].a, y =E[e].b;
		if(isC[x] == isC[y]) continue;
		x =isC[x], y =isC[y];
		if(C[x].size() < C[y].size()) swap(x,y);
		// y do x
		if((int)(C[x].size()+C[y].size()) >= T) {
			if((int)C[x].size() < T)
				for(uint j =0; j < C[x].size(); j++) D[C[x][j]] =E[e].d;
			if((int)C[y].size() < T)
				for(uint j =0; j < C[y].size(); j++) D[C[y][j]] =E[e].d;
			}
		for(uint j =0; j < C[y].size(); j++) {
			isC[C[y][j]] =x;
			C[x].push_back(C[y][j]);}
		}

	long long ans =0;
	for(int i =0; i < N*M; i++) {
		int a;
		scanf(" %d",&a);
		ans +=a*(long long)(D[i]);}
	printf("%lld\n",ans);
	return 0;}

// look at my code
// my code is amazing