#include <stdio.h>
#include <string.h>
#include <string>
#include <vector>
#include <sstream>
#include <algorithm>
#include <iostream>
#include <cmath>
#include <map>
#include <queue>
using namespace std;

#define FOR(i,n) for (int i = 0; i < n; i++)
#define abs(x) ((x)<0?(-(x)):(x))
#define REP(i,v) for (unsigned i = 0; i < v.size(); i++)
#define RL(i,v) for (unsigned i = 0; i < v.length(); i++)
typedef long long ll;

// EXAM
#define MAX_SIZE 550
string field[MAX_SIZE];
bool visited[MAX_SIZE][MAX_SIZE];

int main()
{
#ifdef __LOCAL__
	freopen("input.in", "r", stdin);
#else
	freopen("exam.in", "r", stdin);
 	freopen("exam.out", "w", stdout);
#endif
    int N,M,A,B,SI,SJ,EI,EJ;
    cin>>N>>M>>A>>B;
    for(int i=0;i<N;i++) {
        string t;
        cin>>field[i];
        //cout<<field[i]<<endl;
    }
    memset(visited,false,sizeof(visited));
    cin>>SI>>SJ>>EI>>EJ;
    SI--;SJ--;EI--;EJ--;
    if(SI==EI && SJ == EJ) {
        cout<<0<<endl;
        return 0;
    }

    priority_queue<pair<long,pair<int,int> > > pq;
    pq.push(make_pair(0,make_pair(SI,SJ)));
    visited[SI][SJ] = true;

    int dy[] = {0,-1,0,1};
    int dx[] = {1,0,-1,0};


    while(!pq.empty()) {
        pair<long,pair<int,int> > now = pq.top();
        pq.pop();
        int ii = now.second.first;
        int jj = now.second.second;
        ll cost = -now.first;
        //cout<<ii<<jj;
        if(ii==EI && jj==EJ) {
            cout<<cost<<endl;
            return 0;
        }
        visited[ii][jj] = true;
        for(int i=0;i<4;i++) {
            int ni = ii + dy[i];
            int nj = jj + dx[i];
            //cout<<"try"<<ni<<" "<<nj<<endl;
            if(ni>=0 && nj>=0 && ni<N && nj<M && !visited[ni][nj]) {
                ll add = B;
                if(field[ii][jj]!=field[ni][nj])add += A;
                pq.push(make_pair(-(cost+add),make_pair(ni,nj)));
            }
        }
    }

    return 0;
}