1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<string> 5 #include<cmath> 6 #include<algorithm> 7 #include<queue> 8 #include<map> 9 #include<stack> 10 #include<vector> 11 12 using namespace std; 13 typedef long long ll; 14 const double eps=1e-6; 15 const int maxn=2e2+2; 16 const int maxm=maxn*maxn; 17 int n,m,k; 18 ll r; 19 struct node{ 20 ll x; 21 ll y; 22 node(ll _x,ll _y):x(_x),y(_y){} 23 }; 24 vector<node> g; 25 bool vis[maxn]; 26 struct Node{ 27 int id; 28 int step; 29 int k; 30 Node(int _id,int _step,int _k):id(_id),step(_step),k(_k){} 31 }; 32 bool judge(int u,int v){ 33 ll tmp=(g[u].x-g[v].x)*(g[u].x-g[v].x)+(g[u].y-g[v].y)*(g[u].y-g[v].y); 34 if(tmp<=r*r) return true; 35 return false; 36 } 37 struct edge{ 38 int to; 39 int nxt; 40 }e[2*maxm]; 41 int tot; 42 int head[maxn]; 43 void init(){ 44 g.clear(); 45 memset(head,-1,sizeof(head)); 46 tot=0; 47 memset(vis,false,sizeof(vis)); 48 } 49 void add(int u,int v){ 50 e[tot].to=v; 51 e[tot].nxt=head[u]; 52 head[u]=tot++; 53 } 54 int bfs(){ 55 int s=1,t=2; 56 queue<Node> Q; 57 Q.push(Node(s,0,0)); 58 while(!Q.empty()){ 59 Node q=Q.front(); 60 Q.pop(); 61 if(q.id==t){ 62 return q.step; 63 } 64 if(vis[q.id]) continue; 65 vis[q.id]=true; 66 int u=q.id; 67 for(int i=head[u];i!=-1;i=e[i].nxt){ 68 int v=e[i].to; 69 if(v<=n){ 70 Q.push(Node(v,q.step+1,q.k)); 71 }else{ 72 if(q.k+1<=k){ 73 Q.push(Node(v,q.step+1,q.k+1)); 74 } 75 } 76 } 77 78 } 79 return -1; 80 } 81 int work(){ 82 return bfs()-1; 83 } 84 int main(){ 85 while(~scanf("%d%d%d%lld",&n,&m,&k,&r)){ 86 init(); 87 ll x,y; 88 g.push_back(node(0,0)); 89 for(int i=1;i<=n;i++){ 90 scanf("%lld%lld",&x,&y); 91 g.push_back(node(x,y)); 92 } 93 for(int i=1;i<=m;i++){ 94 scanf("%lld%lld",&x,&y); 95 g.push_back(node(x,y)); 96 } 97 for(int i=1;i<=n+m;i++){ 98 for(int j=i+1;j<=n+m;j++){ 99 if(judge(i,j)){ 100 add(i,j); 101 add(j,i); 102 } 103 } 104 } 105 int ans=work(); 106 printf("%d ",ans); 107 } 108 return 0; 109 }