#ifdef _WIN32
#  define LL "%I64d"
#else
#  define LL "%Ld"
#endif

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <ctime>
#include <vector>
#include <deque>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <bitset>
#include <string>
#include <algorithm>
#include <complex>
#include <utility>
using namespace std;
#define null NULL
#define mp make_pair
#define pb(a) push_back(a)
#define sz(a) ((int)(a).size())
#define all(a) a.begin() , a.end()
#define fi first
#define se second
#define relaxMin(a , b) (a) = min((a),(b))
#define relaxMax(a , b) (a) = max((a),(b))
#define SQR(a) ((a)*(a))
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef long long ll;
#define INF 1000000000000000LL
int N , M , A , B;
int Sx , Sy , Ex , Ey;
char T[510][510];
int sft[4][2] = {{-1,0},{1,0},{0,-1},{0,1}};
bool is_in(int x , int y){
  return x>=0 && x<N && y>=0 && y<M;
}
ll sp[510][510];
struct compare{
  bool operator()(const pii& f , const pii& s)const{
   return sp[f.fi][f.se] != sp[s.fi][s.se] ?
          sp[f.fi][f.se] < sp[s.fi][s.se]  :
          f < s;
                                                   }
};
set<pii , compare> U;
ll djikstra(){
  for(int i=0;i<N;++i)
   for(int j=0;j<M;++j)
    sp[i][j] = INF;
  sp[Sx][Sy] = 0;
  U.insert(mp(Sx , Sy));
  while(!U.empty()){
   pii C = *U.begin();
   U.erase(C);
   if(C.fi == Ex && C.se == Ey)
    return sp[Ex][Ey];
   ll val = sp[C.fi][C.se];
   char DIG = T[C.fi][C.se];
   for(int p=0;p<4;++p){
    int nx = C.fi + sft[p][0] , ny = C.se + sft[p][1];
    if(!is_in(nx , ny))continue;
    ll nval = val + B + (DIG == T[nx][ny] ? 0 : A);
    if(sp[nx][ny] > nval){
     U.erase( mp(nx , ny) );
     sp[nx][ny] = nval;
     U.insert( mp(nx , ny) );
                         }
                       }
                   }
  return sp[Ex][Ey]; // not get here
}
int main(){
  freopen("exam.in" , "r" , stdin);
  freopen("exam.out" , "w" , stdout);
  scanf("%d%d%d%d" , &N , &M , &A , &B);
  for(int i=0;i<N;++i)
   scanf("%s" , &T[i]);
  scanf("%d%d" , &Sx , &Sy);
  scanf("%d%d" , &Ex , &Ey);
  --Sx , --Sy;
  --Ex , --Ey;
  cout<<djikstra()<<'\n';
  return 0;
}
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