import java.util.*;
import java.lang.*;
import java.io.*;

class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

        st = new StringTokenizer(br.readLine());
        int N = Integer.parseInt(st.nextToken());
        int M = Integer.parseInt(st.nextToken());
        int K = Integer.parseInt(st.nextToken());

        st = new StringTokenizer(br.readLine());
        long X = Long.parseLong(st.nextToken());
        long Y = Long.parseLong(st.nextToken());

        int[] A = new int[N];
        st =  new StringTokenizer(br.readLine());
        for (int i=0; i<N; i++) {
            A[i] = Integer.parseInt(st.nextToken());
        }
        
        int[] B = new int[M];
        st =  new StringTokenizer(br.readLine());
        for (int i=0; i<M; i++) {
            B[i] = Integer.parseInt(st.nextToken());
        }

        Arrays.sort(A);
        Arrays.sort(B);


        long[] A_acc = new long[N+1];
        for (int i=1; i<=N; i++) {
            A_acc[i] = A_acc[i-1] + A[i-1];
        }

        
        int max_v = 0;
        long[] remains = new long[M+1];
        remains[0] = X + K*Y;
        for (int i=1; i<=M; i++) {
            if(Y*K >= B[i-1]) {
                remains[i] = remains[i-1] - B[i-1];
                Y -= (K+B[i-1]-1)/K;

                int l = 0;
                int r = N;
                // while(l != r) {
                while(l <= r) {
                    int m = (l+r)/2;
                    if(remains[i] >= A_acc[m]) {
                        max_v = Math.max(max_v, i+m);
                        l = m+1;
                    } else {
                        r = m-1;
                    }
                }
                // 난 l != r 혹은 l<r로 함. 그리고 l=m, r=m으로 갱신했었는데...
                
            } else {
                break;
            }
        }
        
        
        System.out.println(max_v);
        
        
        
        
    }
}