2396: Savior
Description
Misha decided to help Pasha and Akim be friends again. He had a cunning plan − to destroy all the laughy mushrooms. He knows that the laughy mushrooms can easily burst when they laugh. Mushrooms grow on the lawns. There are a[t] mushrooms on the t-th lawn.
Misha knows that the lawns where the mushrooms grow have a unique ability. A lawn (say, i) can transfer laugh to other lawn (say, j) if there exists an integer (say, b) such, that some permutation of numbers a[i],a[j] and b is a beautiful triple (i≠j). A beautiful triple is such three pairwise coprime numbers x,y,z, which satisfy the following condition: x2+y2=z2.
Misha wants to know on which minimal number of lawns he should laugh for all the laughy mushrooms to burst.
The first line contains one integer n (1≤n≤106) which is the number of lawns. The next line contains n integers ai which are the number of mushrooms on the i-lawn (1≤ai≤107). All the numbers are different.
Print a single number − the minimal number of lawns on which Misha should laugh for all the mushrooms to burst.
1
2
1
2
1 2
2
2
3 5
1