#include<bits/stdc++.h>
using namespace std;
const int N=1919810;
typedef long long ll;
typedef pair<ll,ll> PII;
ll n,m,k;
ll a[N],b[N];
char s[N];
ll c,d;
ll ss[N];


bool check(ll mid){
    for(int i=1;i<=n;i++) b[i]=a[i]-mid;
    for(int i=1;i<=n;i++){
        if(b[i]>=0) ss[i]=1;
        else ss[i]=0;
        ss[i]+=ss[i-1];
    }
    ll ad=0;
    for(int i=1;i<=n;i++){
        b[i]+=ad;
        ad+=d;
    }
    // for(int i=1;i<=n;i++) cout<<b[i]<<" ";
    // cout<<endl;
    priority_queue<PII,vector<PII>,greater<PII>> q;
    ll minus=-c;
    ll mx=0;
    // cout<<ss[n]<<endl;
    for(int i=1;i<=m;i++) q.push({b[i],i});
    ll cnt=m,cnt2=0;
    
    for(int i=1;i+m-1<=n;i++){
        while(q.size()&&(q.top().first-minus)<0){
            if(q.top().second<i) cnt2++;
            q.pop();
        }
        // cout<<cnt<<" "<<cnt2<<endl;
        ll tot=q.size()-cnt2;
        tot+=(ss[n]-(ss[i+m-1]-ss[i-1]));
        // cout<<(ss[i+m-1]-s[i-1])<<endl;
        // cout<<i<<" "<<se.size()<<" "<<tot<<endl;
        // if(!se.count({b[i],i})&&b[i]+c>=0) tot++;
        mx=max(mx,tot);
        // cnt2++;
        if(b[i]-minus>=0) cnt2++;
        // if(se.count({b[i],i})) se.erase(se.find({b[i],i}));
        q.push({b[i+m],i+m});
        // cnt++;
        minus+=d;
    }
    // cout<<mid<<" "<<mx<<" "<<k<<endl;
    return mx>=k;
}

int main(){
    cin>>n>>k>>m;
    cin>>c>>d;
    for(int i=1;i<=n;i++) scanf("%lld",&a[i]);
    // check(9);
    ll l=0,r=1e15;
    while(l<r){
        ll mid=l+r+1>>1;
        if(check(mid)) l=mid;
        else r=mid-1;
    }
    cout<<l<<endl;
}