#define _CRT_SECURE_NO_DEPRECATE
#include <iostream> 
#include <string>
#include <vector>
#include <sstream>
#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 mpair make_pair
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
typedef long double ld;
const ld epsylon = 1e-9;

int move[4][2] = {{-1,0},{0,1},{1,0},{0,-1}};
int main()
{
  freopen("exam.in","r",stdin);
  freopen("exam.out", "w", stdout);

  int n,m, A,B;
  cin >> n >> m >> A >> B;
  vector<string> a(n);
  getline(cin, a[0]);
  for (int i =0;i<n;++i) {
    getline(cin, a[i]);
  }

  int sx, sy;
  int tx, ty;
  cin >> sx >> sy >> tx >>ty;

  sx--;
  sy--;
  tx--;
  ty--;

  vector<vector<int> > d(n, vector<int>(m, -1));

  vector<vector<int> > vis(n, vector<int>(m, 0));
  priority_queue<pair<int,pair<int,int>  > > tc;
  tc.push(mpair(0, mpair(sx, sy)));

  d[sx][sy] = 0;
  while (!tc.empty() && vis[tx][ty] == 0) {
    int cx = tc.top().second.first;
    int cy = tc.top().second.second;

    int dist = -tc.top().first;
    tc.pop();

    if ( vis[cx][cy] ) {
      continue;
    }

    vis[cx][cy] = 1;

    for (int l = 0;l<4;++l){
      int ttx = cx + move[l][0];
      int tty = cy + move[l][1];
      if (ttx <0  || ttx >= n || tty < 0 || tty >= m) {
        continue;
      }

      if ( vis[ttx][tty]) {
        continue;
      }

      int add = B;
      if (a[ttx][tty] != a[cx][cy]) {
        add += A;
      }
      if ( d[ttx][tty] == -1 || dist +add < d[ttx][tty]) {
        d[ttx][tty] = dist +add;
        tc.push(mpair(-d[ttx][tty], mpair(ttx, tty)));
      }
    }
  }

  cout << d[tx][ty] << endl;
  return 0;
}
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