#include<bits/stdc++.h>
using namespace std;
const int maxn=2005;
double f[maxn][20][20],g[maxn][20],p[maxn],t1,t2;
double inf=1e9;
int H,S,k;
int n;
bitset<maxn>hav;
int main(){
	cin.tie(0),cout.tie(0),ios::sync_with_stdio(false);
	cin>>n>>H>>S;
	for(int i=1;i<=n;i++)cin>>p[i],p[i]/=100.0;
	cin>>k;
	for(int i=1;i<=k;i++){
		int pos;
		cin>>pos;
		hav[pos]=1;
	}
	cin>>t1>>t2;
	if(t1>=t2||!S){
		for(int i=n;i>=1;i--){
			g[i][2]=(g[i+2][2]*p[i]+(1-p[i])*t2+1)/p[i];
			for(int j=3;j<=n;j++)g[i][j]=1+p[i]*g[i+1][j]+(1-p[i])*g[i][j-1];
		}
		cout<<setprecision(10)<<g[1][H]<<"\n";
	} else {
		for(int i=n;i>=1;i--){
			if(hav[i]){
				for(int h=2;h<=H;h++)for(int s=0;s<=S;s++)g[h][s]=inf;
				for(int L=2;L<=H;L++){
					f[i][L][S]=(f[i+1][L][S]*p[i]+(1-p[i])*t1+1)/p[i];
					for(int h=L+1;h<=H;h++)f[i][h][S]=1+f[i+1][h][S]*p[i]+(1-p[i])*f[i][h-1][S];
					for(int h=2;h<L;h++)f[i][h][S]=(L-h)*t1+f[i][L][S];
					for(int h=2;h<=H;h++)for(int s=0;s<S;s++)f[i][h][s]=f[i][h][S];
					for(int h=2;h<=H;h++)for(int s=0;s<=S;s++)g[h][s]=min(g[h][s],f[i][h][s]);
				}
				for(int h=2;h<=H;h++)for(int s=0;s<=S;s++)f[i][h][s]=g[h][s];
			} else {
				for(int h=2;h<=H;h++){
					for(int s=0;s<=S;s++){
						if(h==2&&s==0)f[i][h][s]=(f[i+1][h][s]*p[i]+(1-p[i])*t2+1)/p[i];
						else if(h==2)f[i][h][s]=f[i+1][h][s]*p[i]+(1-p[i])*(f[i][h][s-1]+t1)+1;
						else f[i][h][s]=1+p[i]*f[i+1][h][s]+(1-p[i])*f[i][h-1][s];
					}
				}
			}
		}
		cout<<setprecision(10)<<f[1][H][S];
	}
	return 0;
}