#include<iostream>
using namespace std;

void nhap(int n, int a[]){
	for(int i=0; i<n; i++){
		cout << "So thu " << i << ": ";
		cin >> a[i];
	}
}

void xuat(int n, int a[]){
	cout << "\nDay so:";
	for(int i=0; i<n; i++){
		cout << " " << a[i];
	}
	cout << endl;
}

void daoNguoc(int n, int a[]){
	cout << "\nDao nguoc day so:";
	for(int i=n-1; i>=0; i--){
		cout << " " << a[i];
	}
}

int chiaHet(int n, int a[]){
	int count = 0;
	for(int i=0; i<n; i++){
		if(a[i] % 3 == 0) count++;
	}
	return count;
}

bool isChinhPhuong(int c){
	if (c == 1) return true;
	for(int i=2; i<=(c/2); i++){
		if(i*i == c) return true;
	}
	return false;
}

int chinhPhuong(int n, int a[]){
	int count = 0;
	for(int i=0; i<n; i++){
		if(isChinhPhuong(a[i])) count++;
	}
	return count;
}

int main(){
	int n; 
	cout << "Nhap n = "; cin >> n;
	int a[n];
	nhap(n, a);
	xuat(n, a);
	daoNguoc(n, a);
	cout << endl << "Day co " << chiaHet(n, a) << " so chia het cho 3.\n";
	cout << "Day co " << chinhPhuong(n, a) << " so chinh phuong.\n";
	return 0;
}