#include<iostream>
using namespace std;
int prim(int x)
{
int d;
if(x<2 || x>2 && x%2==0)
return 0;
for(d=3;d*d<=x;d+=2)
if(x%d==0)
return 0;
return 1;
}
int main()
{
int v[100],i,n,minim=999999;
cin>>n;
for(i=0;i<n;i++)
{
cin>>v[i];
if(v[i]<minim && prim(v[i])==1)
minim=v[i];
}
cout<<minim;
return 0;
}