#include #include int q[1048576]; int qp=0,qqp=0; void qpush(int x){ qp++;q[qp]=x; } int qpop(){ qqp++; return q[qqp]; } int dsc[512][512]={0}; int sid[512][512]; int res[524288],rc=0; bool isvalid(int a,int b){ if(a<0||a>500){return false;} if(b<0||b>500){return false;} return true; } void rem(int a,int b){ if(sid[a][b]==-1){return;} sid[a][b]=-1; int i,j,x,y; for(i=-10;i<=10;i++){ for(j=-10;j<=10;j++){ if((i*i+j*j)>=100){continue;} x=a+i;y=b+j; if(isvalid(x,y)){ if(sid[x][y]!=-1){ dsc[x][y]--; if(dsc[x][y]<=89){ dsc[x][y]=1000000007; qpush(x*512+y); } } } } } } void sit(int a,int b){ if(sid[a][b]==-1){return;} res[rc]=sid[a][b]; rc++; int i,j,x,y; for(i=-10;i<=10;i++){ for(j=-10;j<=10;j++){ if((i*i+j*j)>=100){continue;} x=a+i;y=b+j; if(isvalid(x,y)){rem(x,y);} } } } int main(){ int i,j,k,n,a,b,x,y; for(i=0;i<512;i++){ for(j=0;j<512;j++){sid[i][j]=-1;} } scanf("%d",&n); for(i=1;i<=n;i++){ scanf("%d%d",&a,&b); sid[a][b]=i; for(j=-10;j<=10;j++){ for(k=-10;k<=10;k++){ if((j*j+k*k)>=100){continue;} x=a+j;y=b+k; if(isvalid(x,y)){dsc[x][y]++;} } } dsc[a][b]--; } for(i=0;i<512;i++){ for(j=0;j<512;j++){ if(sid[i][j]!=-1 && dsc[i][j]<=89){ dsc[i][j]=1000000007; qpush(i*512+j); } } } while(qp!=qqp){ x=qpop(); sit(x/512,x%512); } printf("%d\n",rc); for(i=0;i