#include<bits/stdc++.h>
using namespace std;
int main(){
	float n,maxx;
	cin>>n;
	cin>>maxx;
	maxx*=n;
	for(int i=2;i<=12;i++){
		cin>>ai;
		maxx=max(ai*n,maxx);
	}
	printf("%.2f",maxx);
}
/**************************************************************
	Problem: 2031
	User: wangyiyang
	Language: C++
	Result: Compile Error
****************************************************************/