#define _CRT_SECURE_NO_DEPRECATE
#include <iostream>
#include <string>
#include <vector>
#include <sstream>

#include <ctime>
#include <queue>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <math.h>
#include <stack>
#include <deque>
#include <numeric>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <bitset>

#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const ld epsylon = 1e-9;
typedef unsigned int ui;
inline long double get_time(){   
	return (long double)clock()/CLOCKS_PER_SEC;
};
//ld start_time,end_time;


vector <pair<int, int> > nbs[250000];

char m3x[501][501];
int n, m;
int a, b;

struct comp {   
	bool operator() (const pair<int, int> &a, const pair<int, int> &b)
	{        return a.second > b.second;    }};

int startedge;
int endedge;
int dist[250000];
int part[250000];
int nodes;
#define INF 1000000000
int dijkstra()
{
	priority_queue<pair <int, int> , vector <pair <int, int> >, comp> pq;
	for (int i = 0; i < nodes; ++i)
	{
		dist[i] = INF;
		part[i] = 0;
	}
	dist[startedge] = 0;
	pq.push(pair<int, int>(startedge, 0));
	int u, sz, v, w;
	while (!pq.empty())
	{
		    u = pq.top().first;
			pq.pop();
			if(part[u]) continue;
			for(int i=0; i<nbs[u].size(); i++) {
				v = nbs[u][i].first;
				w = nbs[u][i].second;
				if(!part[v] && dist[u]+w < dist[v]) {
					dist[v] = dist[u] + w;
					pq.push(pair<int, int> (v, dist[v])); 
				}        } 
			part[u] = 1; // done with u
	}
	return dist[endedge];
}

int main()
{
	freopen("exam.in","r",stdin);
	freopen("exam.out","w",stdout);
	//start_time = get_time();
	//program
	char line[501];
	scanf("%d %d %d %d\n", &n, &m,&a,&b);
	for (int i = 0; i < n; ++i)
	{
		scanf("%s\n", m3x[i]);
	}
	int num = 0;
	int starti, startj, endi, endj;
	scanf("%d %d %d %d", &starti,&startj,&endi,&endj);
	for (int i = 0; i < n; ++i)
	{
		for (int j = 0; j < m; ++j)
		{
			if (i-1 >= 0) nbs[num].push_back(pair<int, int>(num-m, (m3x[i][j] != m3x[i-1][j]) ? a+b : b));
			if (i+1 < n) nbs[num].push_back(pair<int, int>(num+m, (m3x[i][j] != m3x[i+1][j]) ? a+b : b));
			if (j-1 >= 0) nbs[num].push_back(pair<int, int>(num-1, (m3x[i][j] != m3x[i][j-1]) ? a+b : b));
			if (j+1 < m) nbs[num].push_back(pair<int, int>(num+1, (m3x[i][j] != m3x[i][j+1]) ? a+b : b));
			num++;
		}
	}

	starti--,startj--,endi--,endj--;
	startedge = starti*m+startj;
	endedge = endi*m+endj;
	nodes = num;
	printf("%d\n", dijkstra());
	//end program
	//end_time=get_time()-start_time;
	return 0;
}




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