#include<cstdio>

#include<cmath>

#include<algorithm>

#include<vector>

#include<queue>

using namespace std;

typedef pair<double,int>PI;

const int N=2100000,M=9100000;

const double eps=1e-6,inf=1e100;

int n,cnt,i,j,g[N],v[M],nxt[M],ed;double w[M],d[N],va,vb,si[2],co[2];

priority_queue<PI,vector<PI>,greater<PI> >q;

inline void add(int x,int y,double z){v[++ed]=y;w[ed]=z;nxt[ed]=g[x];g[x]=ed;}

inline void add2(int x,int y,double z){add(x,y,z),add(y,x,z);}

inline void ext(int x,double y){if(y+eps<d[x])q.push(PI(d[x]=y,x));}

inline int sgn(double x){

  if(x>eps)return 1;

  if(x<-eps)return -1;

  return 0;

}

struct P{

  double x,y;

  P(){}

  P(double _x,double _y){x=_x,y=_y;}

  P operator+(P b){return P(x+b.x,y+b.y);}

  P operator-(P b){return P(x-b.x,y-b.y);}

  P operator*(double b){return P(x*b,y*b);}

  P operator/(double b){return P(x/b,y/b);}

  double operator*(P b){return x*b.x+y*b.y;}

  bool operator==(P b){return !sgn(x-b.x)&&!sgn(y-b.y);}

  double len(){return hypot(x,y);}

  P rotate(double s,double c){return P(x*c-y*s,x*s+y*c);}

  P rot90(){return P(-y,x);}

}a[1010];

struct E{

  double x;int y;

  E(){}

  E(double _x,int _y){x=_x,y=_y;}

}e[2010];

inline bool cmp(const E&a,const E&b){return a.x<b.x;}

inline double cross(P a,P b){return a.x*b.y-a.y*b.x;}

inline bool point_on_segment(P p,P a,P b){

  return sgn(cross(b-a,p-a))==0&&sgn((p-a)*(p-b))<=0;

}

inline P line_intersection(P a,P b,P p,P q){

  double U=cross(p-a,q-p),D=cross(b-a,q-p);

  return a+(b-a)*(U/D);

}

inline void work(int st,int en){

  int i,j,m=2;

  P A=a[st],B=a[en],C=(B-A).rot90();

  e[1]=E(0,st),e[2]=E(C.len(),en);

  for(i=0;i<=n;i++)if(i!=st&&i!=en)for(j=0;j<2;j++){

    P D=line_intersection(A,B,a[i],a[i]+C.rotate(si[j],co[j]));

    if(D==A||D==B)continue;

    if(!point_on_segment(D,A,B))continue;

    cnt++;

    add2(i,cnt,(a[i]-D).len()/vb);

    e[++m]=E((D-A).len(),cnt);

  }

  sort(e+1,e+m+1,cmp);

  for(i=1;i<m;i++)add2(e[i].y,e[i+1].y,(e[i+1].x-e[i].x)/va);

}

int main(){

  scanf("%d%lf%lf",&n,&va,&vb);

  for(i=1;i<=n;i++)scanf("%lf%lf",&a[i].x,&a[i].y);

  if(sgn(va-vb)<=0)return printf("%.10f",(a[0]-a[n]).len()/vb),0;

  si[0]=vb/va;

  co[0]=sqrt(1.0-si[0]*si[0]);

  si[1]=-si[0];

  co[1]=co[0];

  cnt=n;

  for(i=0;i<=n;i++)for(j=0;j<i;j++)add2(i,j,(a[i]-a[j]).len()/vb);

  for(i=0;i<n;i++)work(i,i+1);

  for(i=0;i<=cnt;i++)d[i]=inf;

  ext(0,0);

  while(!q.empty()){

    PI t=q.top();q.pop();

    if(t.first-eps>d[t.second])continue;

    for(i=g[t.second];i;i=nxt[i])ext(v[i],t.first+w[i]);

  }

  return printf("%.10f",d[n]),0;

}