#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1);
const double eps = 1e-12;
const int inf = 2000000000;
const long long int infLL = (long long int)2e18;
long long int MOD = 1000000007;
int MOD1 = 1000000007;
int MOD2 = 1000000009;
inline bool checkBit(long long int n, long long int i) {
  return n & (1LL << i);
}
inline long long int setBit(long long int n, long long int i) {
  return n | (1LL << i);
  ;
}
inline long long int resetBit(long long int n, long long int i) {
  return n & (~(1LL << i));
}
int dx[] = {0, 0, +1, -1};
int dy[] = {+1, -1, 0, 0};
inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }
inline bool isLeapYear(long long int year) {
  return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);
}
inline void normal(long long int &a) {
  a %= MOD;
  (a < 0) && (a += MOD);
}
inline long long int modMul(long long int a, long long int b) {
  a %= MOD, b %= MOD;
  normal(a), normal(b);
  return (a * b) % MOD;
}
inline long long int modAdd(long long int a, long long int b) {
  a %= MOD, b %= MOD;
  normal(a), normal(b);
  return (a + b) % MOD;
}
inline long long int modSub(long long int a, long long int b) {
  a %= MOD, b %= MOD;
  normal(a), normal(b);
  a -= b;
  normal(a);
  return a;
}
inline long long int modPow(long long int b, long long int p) {
  long long int r = 1LL;
  while (p) {
    if (p & 1) r = modMul(r, b);
    b = modMul(b, b);
    p >>= 1LL;
  }
  return r;
}
inline long long int modDiv(long long int a, long long int b) {
  return modMul(a, modPow(b, MOD - 2));
}
bool comp(const pair<long long int, pair<long long int, long long int> > &p1,
          const pair<long long int, pair<long long int, long long int> > &p2) {
  return p1.first > p2.first;
}
bool comp1(const pair<long long int, long long int> &p1,
           const pair<long long int, long long int> &p2) {
  if (p1.first == p2.first) {
    return p1.second > p2.second;
  }
  return p1.first < p2.first;
}
long long int converter(string a) {
  long long int i, mul = 1, r, t, ans = 0LL;
  if (a.length() == 0) return 0;
  for (i = a.length() - 1; i >= 0; i--) {
    t = a[i] - '0';
    r = t % 10;
    ans += (mul * r);
    mul = mul * 10;
  }
  return ans;
}
int msb(unsigned x) {
  union {
    double a;
    int b[2];
  };
  a = x;
  return (b[1] >> 20) - 1023;
}
const int MAX = (int)1e5 + 5;
pair<long long int, long long int> dis[2005][2005];
pair<long long int, long long int> par[2005][2005];
bool vis[2005][2005];
string s[2005];
int n, m, x, y, l, r;
int oka(int x, int y) {
  if (x >= 1 && y >= 1 && x <= n && y <= m && s[x][y] == '.')
    return 1;
  else
    return 0;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int i, j;
  cin >> n >> m;
  cin >> x >> y;
  cin >> l >> r;
  for (i = 1; i <= n; ++i) {
    string st;
    cin >> st;
    s[i] = '#' + st;
  }
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= m; ++j)
      dis[i][j] = pair<long long int, long long int>(infLL, infLL);
  }
  priority_queue<pair<pair<long long int, long long int>,
                      pair<long long int, long long int> >,
                 vector<pair<pair<long long int, long long int>,
                             pair<long long int, long long int> > >,
                 greater<pair<pair<long long int, long long int>,
                              pair<long long int, long long int> > > >
      q;
  q.push(pair<pair<long long int, long long int>,
              pair<long long int, long long int> >(
      pair<long long int, long long int>(0, 0),
      pair<long long int, long long int>(x, y)));
  dis[x][y] = pair<long long int, long long int>(0, 0);
  while (!q.empty()) {
    long long int u = q.top().second.first;
    long long int v = q.top().second.second;
    if (dis[u][v] < q.top().first) {
      q.pop();
      continue;
    }
    q.pop();
    for (i = 0; i < 4; ++i) {
      int xx = u + dx[i];
      int yy = v + dy[i];
      if (!oka(xx, yy) ||
          par[u][v] == pair<long long int, long long int>(xx, yy))
        continue;
      long long int w1 = (dis[u][v].first + (i == 1));
      long long int w2 = (dis[u][v].second + (i == 0));
      if (dis[xx][yy] <= make_pair(w1, w2)) continue;
      dis[xx][yy] = make_pair(w1, w2);
      par[xx][yy] = make_pair(u, v);
      q.push(pair<pair<long long int, long long int>,
                  pair<long long int, long long int> >(
          dis[xx][yy], pair<long long int, long long int>(xx, yy)));
    }
  }
  int ans = 0;
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= m; ++j)
      ans += (dis[i][j].first <= l && dis[i][j].second <= r);
  }
  cout << ans << '\n';
  return 0;
}
