#include <stdio.h>#include<stdio.h>
int main(){
int n,max,min,curr;
scanf("%d",&n);
scanf("%d",&curr);
max=curr;
min=curr；
for(int i=1;i<n;i++){
scanf("%d",&curr);
if(curr>max){
max=curr;
}if(curr<min){
min=curr;
}
}
printf("%d\n",max*min);
return 0;
}