for(ll n=1; n<100000; n++){
      t=k+2*n-1;
      if((t-n)%(2*n+1)==0&&(t-n)/(2*n+1)>=n){
         v.pb(mp((t-n)/(2*n+1),n));
      }
      t=k+2*n;

      if((t-n)%(2*n+1)==0&&(t-n)/(2*n+1)>n){
         v.pb(mp(n,(t-n)/(2*n+1)));
      }
   }