180201_1037_약수

//https://www.acmicpc.net/problem/1037 #include <iostream>

#include <algorithm>

using namespace std;

int num[51];

int main(){

int A,N;

cin >> N;

int a,b,bin;

if(N==1){

cin >> a;

cout << a*a;

return 0;

}

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

cin >> num[i];

}

sort(num,num+N);

cout << num[0]*num[N-1];

}