#include <bits/stdc++.h>
#define REP(i, a, n) for(ll i = ((ll) a); i < ((ll) n); i++)
using namespace std;
typedef long long ll;

ll W, H, V, T, X, Y, P, Q;

ll solve(ll p, ll q) {
  ll r = V * T;

  ll ret = 0;
  for(ll n = -2000000; n <= 2000000; n++) {
    ll x = 2 * n * W + p - X;

    if(-r <= x && x <= r) {
      ll init = 334;
      REP(i, -1, 2) {
        ll y = 2 * i * H + q - Y;
        if(x * x + y * y <= r * r) init = i;
      }
      if(init == 334) continue;

      ll ok1 = init, ng1 = 2000000;
      while(abs(ng1 - ok1) > 1) {
        ll m = (ok1 + ng1) / 2;
        ll y = 2 * m * H + q - Y;
        (y <= sqrt(r * r - x * x) ? ok1 : ng1) = m;
      }

      ll ok2 = init, ng2 = -2000000;
      while(abs(ng2 - ok2) > 1) {
        ll m = (ok2 + ng2) / 2;
        ll y = 2 * m * H + q - Y;
        (y >= -sqrt(r * r - x * x) ? ok2 : ng2) = m;
      }

      ret += ok1 - ok2 + 1;

      // ll y1 = 2 * ok1 * H + q - Y, y2 = 2 * ok2 * H + q - Y;
      // cerr << "(" << x << ", " << y1 << "), " << "(" << x << ", " << y2 << ")" << endl;
    }
  }

  return ret;
}

int main(void) {
  cin >> W >> H >> V >> T >> X >> Y >> P >> Q;

  ll ans = 0;
  ans += solve(+P, +Q);
  ans += solve(+P, -Q);
  ans += solve(-P, +Q);
  ans += solve(-P, -Q);
  cout << ans << endl;
}

