#include <iostream>

using namespace std;

int main()
{
    int n,r,t,l;
    cin >>n >>r>>t>>l;
    int arr[n];
    for(int i = 0; i < n; i++)
            cin >> arr[i];

    bool zold = true;
    int minlepes = 0;
    for(int i = 0; i < l; i++)
    {
        if((i+1)%t == 0)
            zold = !zold;

        //cout << zold << "\n";
        minlepes++;
        if((i+1) == arr[0]){
            if(zold)
                minlepes+=1;
            else{
                if(!zold){
                    if(r > 0){
                        minlepes++;
                        r--;
                    }
                    else if (r == 0){
                       // cout << "asd";
                        minlepes+=(t - ((i+1)%t));
                    }
                }
            }
        }
        //cout << "i = " << i+1 << '\n';
       // cout << "Minl " << minlepes << '\n';

    }
    cout << minlepes;
    return 0;
}