#include<iostream>
using namespace std;
const int N = 100;
int hl[N+1];
double m[N+1];
int max(int a,int b)
{
	return (a>b)?a:0;
}
int min(int a,int b)
{
	return (a<b)?a:0;
}
int main()
{
    int n;
    cin >> n;
    bool ism = false;
    for(int i=1;i<=n;i++)
    {
    	cin >> hl[i];
	}
	m[0]=100.00; 
	for(int i=1;i<n;i++)
	{
		if(!ism)
		{
			double bh = max(hl[i],hl[i+1]);
			if(bh==0)
			{
				continue;
			}
			m[i] = m[i-1]/100.00*hl[i];
			ism = true;
		}
		else
		{
			double lh = min(hl[i],hl[i+1]);
			if(lh==0)
			{
				continue;
			}
			m[i] = m[i-1]*1.00/hl[i]*100.00;
			ism = false;
		}
	}
	if(ism=true)
	{
		m[n] = m[n-1]*1.00/hl[n]*100.00;
	}
	else
	{
		m[n] = m[n-1]/100.00*hl[n];
	}
	cout << m[n];
	return 0;
}

样例直接爆$\ 0$