#include<stdio.h>
#include<iostream.h>
int main()
{
  int n[15],i=0,j,twice=0;
  cin>>n[i];
  while(n[i]!=-1)
    {
      cin>>n[++i];
      if(n[i]==0)
    {
          cout<<twice<<endl;
      twice=0;
      i=0;
      cin>>n[i];
    }
     else
    {
      for(j=0;j<i;j++)
         {
        if(n[j]==2*n[i]||n[i]==2*n[j])
        twice++;
         }
    }
    }
return 0;
}

评论