#include <bits/stdc++.h>

using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}
template<class T> inline T sqr(T x) {return x*x;}

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a)  (a).begin(),(a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define exist(s,e) ((s).find(e)!=(s).end())
#define range(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)  range(i,0,n)
#define clr(a,b) memset((a), (b) ,sizeof(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi  = acos(-1.0);
const ll INF =1LL << 62;
const int inf =1 << 29;

ll w,h,v,t,x,y,p,q;

inline ll xget(ll i){
	ll res=p;
	if(i&1){
		res+=2*(w-p);
		res+=w*(i-1);
	}else{
		res+=w*i;
	}
	return res;
}

inline ll yget(ll i){
	ll res=q;
	if(i&1){
		res+=2*(h-q);
		res+=h*(i-1);
	}else{
		res+=h*i;
	}
	return res;
}


int main(void){
	cin >> w >> h >> v >> t >> x >> y >> p >> q;
	ll ans=0;
	ll d=(v*t)*(v*t);
	int dmax=(v*t)/w+10;
	for(int i=-dmax;i<=dmax;++i){
		ll xcur=xget(i)-x;
		ll ycursq=d-xcur*xcur;
		if(ycursq<0) continue;
		ll ylimit=sqrt(ycursq)/h;
		ll l=-1,r=ylimit+10;
		while(r-l>1){
			ll m=(r+l)/2;
			ll ycur=yget(m)-y;
			if(ycur*ycur<=ycursq)
				l=m;
			else
				r=m;
		}
		ll upper=l;
		l=-ylimit-10,r=1;
		while(r-l>1){
			ll m=(r+l)/2;
			ll ycur=yget(m)-y;
			if(ycur*ycur<=ycursq)
				r=m;
			else
				l=m;
		}
		ll lower=r;
		ll cur=0;
		if(lower<=0) cur-=lower;
		if(0<=upper) cur+=upper;
		if(lower<=upper) cur++;
		ans+=cur;
	}
	cout << ans << endl;
	return 0;
}