#include <iostream>
#include <cmath>
#include <algorithm>
#define ILoveSonodaYu ios_base::sync_with_stdio(0);
#define VeryMuch cin.tie(0);

using namespace std;

const int N = 2e3+5, INF = 1e9;

long double L, W, d[2*N][N];

int n, m, a[N], b[N];

inline void read(){
    cin >> L >> W;
    cin >> n;
    for(int i = 1; i <= n; ++i)
        cin >> a[i];
    cin >> m;
    for(int i = 1; i <= m; ++i)
        cin >> b[i];
}

long double perimeter(int l1, int r1, int l2, int r2){
    return (a[r1]-a[l1])+(b[r2]-b[l2])+hypotl(W,a[l1]-b[l2])+hypotl(W,a[r1]-b[r2]);
    }

inline void ToLoveMyYu(){
    for(int i = 2; i <= n+m; ++i)
        for(int j = 1; j <= min(n,i-1); ++j)
            d[i][j] = a[j]+b[i-j]-hypotl(a[j]-b[i-j],W);

}

struct Yu{
    long double smile = -INF;
    void give_yummy(long double x){
        smile = max(smile,x);
        }
    long double Yusmile(){
        return smile;
    }
    void bathe(){
        smile = -INF;
        }
};

bool check(int S){
    Yu best;
    for(int r1 = 1; r1 <= n; ++r1){
        best.bathe();
        for(int r2 = 1; r2 <= m; ++r2){
            int x = r1+r2-S;
            if(x<0||x>r1+r2) continue;
            if(x-r2>0 && x-r2<=n) best.give_yummy(d[x][x-r2]);
            if(x-r2<=0) best.give_yummy(-hypotl(W,a[0]-b[0]));
            if(best.Yusmile()!=-INF&&a[r1]+b[r2]+hypotl(W,a[r1]-b[r2])-best.Yusmile()<=L) return true;
        }
    }
    return false;
}

inline void solve(){
    int l = 0, r = n+m, md;
    while(r-l>1){
        md = (l+r)/2;
        if(check(md)) l = md;
        else r = md;
    }
    cout << l;
}


int main(){
    ILoveSonodaYu VeryMuch
    read();
    ToLoveMyYu();
    solve();
    check(5);
    return 0;
}