using System;

public class Program {

public static int[] prime = new int[168]{2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,751,757,761,769,773,787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,971,977,983,991,997};

public static bool[] used = new bool[168];

public static int len;

public static int[] list;

public static int[,] primesOf;

public static int min = 0x3f3f3f3f;

public static void dfs(int deep,int sum){

if(deep==len){

if(sum<min)min=sum;

// Console.WriteLine(sum);

return;

}

for(int i = 0;primesOf[deep,i]!=0;i++){

if(used[primesOf[deep,i]-1])continue;

used[primesOf[deep,i]-1]=true;

dfs(deep+1,sum+prime[primesOf[deep,i]-1]);

used[primesOf[deep,i]-1]=false;

}

}

public static void Main() {

len = int.Parse(Console.ReadLine());

list = new int[len];

primesOf = new int[len,84+1];

int temp = 0;

foreach(string str in Console.ReadLine().Split(' ')){

list[temp]=int.Parse(str);

temp++;

}

for(int i = 0;i<len;i++){

temp = 0;

for(int j = 0;j<prime.Length;j++){

if(prime[j]>list[i])break;

if(list[i]%prime[j]!=0)continue;

primesOf[i,temp]=j+1;

temp++;

}

}

dfs(0,0);

if(min==0x3f3f3f3f)min=-1;

Console.WriteLine(min);

}

}