题解：UVA12802 Gift From the Gods

#include <bits/stdc++.h>
using namespace std;
bool prm(int a)
{
	if (a < 2) return 0;
	for (int i = 2; i * i <= a; i ++)
		if (a % i == 0)
			return 0;
	return 1;
}//判素数
bool hw (int a)
{
	int cnt = 0;
	int a2 = a;//拷贝一下
	while (a2)
	{
		cnt = cnt * 10 + a2 % 10;
		a2 /= 10;
	}
	return cnt == a;
}//判断是否回文
int main()
{
	while (1)
	{
		int a;
		cin >> a;
		a *= 2;
		cout << a << endl;
		if (hw (a) && prm(a)) break;//都满足
	}
	return 0;
}

while ((cin >> a))
{
    cout << 2a << endl;
}