C :

#include<stdio.h>

int main()
{
	double n,a[12],max;
	int i;
	scanf("%lf",&n);
	for(i=0;i<12;i++)
		scanf("%lf",&a[i]);
	max=a[0];
	for(i=1;i<12;i++)
		if(max<a[i])
			max=a[i];
	printf("%.2lf\n",n*max);
	return 0;
}

C++ :

#include <stdio.h>

int main()
{
	float money;
	while(scanf("%f",&money)!=EOF)
	{
		float change;
		float max=0;
		for(int i=0;i<12;i++)
		{
			scanf("%f",&change);
			if(max<change)
				max=change;
		}
		printf("%.2f\n",max*money);
	}
	return 0;
}

Java :

import java.util.Scanner;

public class Main {
	//转换int成为ascii码值
	/*
	 public static char toChar(int prefix){
		return (char) prefix;
	}
	*/
	//输入整型
	/*
	public static int scanfInt(){
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		return sc.nextInt();
	}
	*/
	//输入float
	/*
	public static float scanfFloat(){
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		return sc.nextFloat();
	}
	*/
	//判断字符c是否在set中
	/*
	public static boolean isInSet(char c){
		if(c == 'A' || c == 'B' || c == 'C' || c == 'D' || c == 'F'){
			return true;
		}
		else
			return false;
	}
	*/
	/*
	public static String judgeEdition(int i){
		if(i == 0)
			return "Same";
		else if(i == 1)
			return "First";
		else
			return "Second";
	}
	*/
	/*
		//版本号相等
			if(edition[i][0][0] == edition[i][1][0]){
				//子版本号相等
				if(edition[i][0][1] == edition[i][1][1]){
					//修订号相等
					if(edition[i][0][2] == edition[i][1][2]){
						result[i] = 0;
					}
					//第一个修订号大
					else if(edition[i][0][2] > edition[i][1][2]){
						result[i] = 1;
					}
					//第二个修订号大
					else 
						result[i] = 2;
				}
				//子版本号第一个大
				else if(edition[i][0][1] > edition[i][1][1]){
					result[i] = 1;
				}
				//子版本号第二个大
				else
					result[i] = 2;
			}
			//版本号第一个大
			else if(edition[i][0][0] > edition[i][1][0]){
				result[i] = 1;
			}
			//版本号第二个大
			else
				result[i] = 2;
	
	
	*/
	public static void main(String[] args){
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		
		float[] rate = new float[12];
		float money = sc.nextFloat();
		float most = 0;
		
		for(int i=0;i<12;i++){
			rate[i] = sc.nextFloat();
			if(money*rate[i] > most){
				most =money * rate[i];
			}
		}
		System.out.println(String.format("%.2f", most));
	}
}