> #include<iostream.h>
>  
> #include<stdio.h>
> #include<math.h>
> __int64 fab(__int64 a)
> {
>      if(a>=0) return a;
>      else  return -a;   
> }
> int main()
> {
>     __int64 x,y,n,sum,m,rest;
>     int N;
>     cin>>N;
>     while(N--)
>     {
>         scanf("%I64d%I64d",&x,&y);
>         m=fab(x-y);
>       if(m==0) cout<<"0"<<endl;
>       else{
>         sum=0; n=1;
>         while((sum+n+n-1)<m)
>         {
>             sum+=(n+n-1);
>             n++;
>         }
>         rest=m-sum;
>         if(rest<n&&rest>0)
>             printf("%I64d\n",2*n-2);
>         else
>             printf("%I64d\n",2*n-1);}
>     }     
>  
>     return 0;
> }


change "#include<iostream.h>"   to

#include<iostream>
using namespace std;

just like this, and you can make it.