#include <iostream>
using namespace std;
#define max 100

void Nhap(int a[], int l);
bool nguyento(int n);
int bai1(int a[], int l);
int bai2(int a[], int l);
int bai3(int a[], int l);
void bai4(int a[], int l);

int main()
{
	int a[max];
	int l;
	int num;
	cout << "nhap so phan tu cua mang: ";
	cin >> l;
	Nhap(a, l);
	cout << "chon chuc nang tu 1 den 4: ";
	cin >> num;
	switch (num)
	{
	case 1: cout << bai1(a, l) << endl; break;
	case 2: cout << bai2(a, l) << endl; break;
	case 3: cout << bai3(a, l) << endl; break;
	case 4: bai4(a, l); break;
	default: cout << "khong co chuc nang so " << num << endl;
		break;
	}
	return 0;
}

void Nhap(int a[], int l) {
	for (int i = 0; i < l; i++)
	{
		cout << "nhap phan tu thu " << i + 1 << ": ";
		cin >> a[i];
		while (a[i] < 1) {
			cout << "nhap lai phan tu thu " << i + 1 << ": ";
			cin >> a[i];
		}
	}
}

bool nguyento(int n) {
	if (n == 1) {
		return false;
	}
	else {
		for (int i = 2; i <= sqrt(n); i++)
		{
			if (n % i == 0) {
				return false;
			}
		}
		return true;
	}
}

int bai1(int a[], int l) {
	int dem = 0;
	for (int i = 0; i < l; i++)
	{
		if (a[i] % 2 == 0) {
			dem+=a[i];
		}
	}
	return dem;
}

int bai2(int a[], int l) {
	for (int i = 0; i < l; i++)
	{
		if ((log10(a[i]) / log10(2)) == int(log10(a[i]) / log10(2))) {
			return a[i];
			break;
		}
	}
	return 0;
}

int bai3(int a[], int l) {
	int dem = 0;
	for (int i = 1; i < l-1; i++)
	{
		if ((a[i] > a[i - 1] && a[i] > a[i + 1]) || (a[i] < a[i - 1] && a[i] < a[i + 1])) {
			dem += a[i];
		}
	}
	return dem;
}

void bai4(int a[], int l) {
	int b[max];
	for (int i = 0; i < l; i++)
	{
		if (nguyento(a[i])) {
			b[i] = a[i];
		}
		else {
			b[i] = a[i] + 1;
			while (nguyento(b[i]) == false) {
				b[i] += 1;
			}
		}
	}
	for (int i = 0; i < l; i++)
	{
		cout << b[i] << " ";
	}
	cout << endl;
}